Mount Si HS Building Assessment Report€¦ · and evaluation document used to identify potential seismic deficiencies that may require additional evaluation or hazard mitigation

Mount Si High School

PREPARED FOR

Building Assessment

May 2013

Snoqualmie Valley School District

PREPARED BY

Snoqualmie Valley School District May 2013 Mount Si High School Building Assessment i

Table of Contents

Page No.

EXECUTIVE SUMMARY ......................................................................................................... II

1.0 INTRODUCTION.................................................................................................................. 1

1.1 Background ........................................................................................................................................ 1 1.2 Criteria ................................................................................................................................................ 1

2.0 FINDINGS .............................................................................................................................. 3

2.1 Structural Systems .............................................................................................................................. 3 2.2 Seismic Deficiencies .......................................................................................................................... 6 2.3 Seismic Deficiency Discussion .......................................................................................................... 7 2.4 Cafeteria Flooding Observations ........................................................................................................ 9

3.0 RECOMMENDATIONS ..................................................................................................... 10

3.1 Options for Additional Analysis and Planning ................................................................................. 10 3.2 Options for Limited Upgrades .......................................................................................................... 12 3.3 Seismic Upgrade Triggers ................................................................................................................ 12 3.4 Cafeteria Flooding ............................................................................................................................ 13

4.0 LIMITATIONS .................................................................................................................... 14

Appendices

Appendix A – Performance-Based Earthquake Engineering (PBEE) Appendix B – ASCE 31-03 Tier 1 Checklists Appendix C – Structural Calculations Appendix D – References/Glossary of Terms

Snoqualmie Valley School District May 2013 Mount Si High School Building Assessment ii

Executive Summary Mount Si High School has been constructed in multiple phases over 50 years. The original construction took place in 1951. The most recent structural work, the Wildcat Court addition, took place in 2010. Building systems used over the years of construction include concrete frames with concrete masonry unit (CMU) infill walls, precast concrete walls, and wood stud walls. The roof and floor framing typically consists of wood decking over wood joists or open web joists with glulam or steel beams. Based on the poor soils in the area, the typical foundation system consists of concrete grade beams spanning between concrete pile caps and piles.

A seismic assessment was performed to investigate potential structural seismic deficiencies. The assessment utilized ASCE 31-03 assessment criteria. ASCE 31 screens an existing building for design elements that have historically performed poorly in earthquakes. It also includes quick-check calculations to examine key seismic force-resisting elements. Some potential deficiencies identified by ASCE 31 may be resolved by more detailed, case-by-case analysis of each condition. Other potential deficiencies highlight details or alignments that should be addressed through supplemental connections or other structural improvements.

A variety of potential seismic deficiencies were noted for Mount Si High School. These deficiencies were generally typical for a building of its era. During the 1990s-era building renovations, some seismic improvements were undertaken. These removed some deficiencies that would otherwise have been expected based on the era and type of construction. Many of the deficiencies warrant additional investigation. Several primary deficiencies appear likely to require supplemental connections in order to address them:

1. Lack of positive connections between the CMU or precast concrete wall panels and the foundations to resist overturning forces and transfer shear. This occurs in several elements of the 1950s and 1960s construction.

2. Potential deficiencies in the out-of-plane connections between the walls and the floor and roof diaphragms. This includes cross-grain bending issues in some ledger connections. This occurs at many floor and roof levels in the 1950s through 1970s construction. The floor level for 1990s construction should also be reviewed with detailed capacity analysis.

3. Lack of top reinforcing steel in the concrete pile caps to resist overturning forces. Lack of reinforcing tying the tops of the piles to the cap structure.

The 1990s-era roof penthouse structure also appears to lack sufficient connection to the roof and supporting structure below. This is not noted as a primary deficiency based on the localized nature of the deficiency; however, the localized aspect of this deficiency may also lend itself to mitigation that is limited in its potential construction disruption to other areas.

Additional, detailed analysis of the potential deficiencies identified is recommended. We understand the district is considering future capital improvement options for the high school. This may create opportunities to include seismic improvements as part of an overall building improvement program. In particular, we recommend that wall-to-foundation, wall-to-floor, and wall-to-roof connectivity issues be prioritized as part of this process. These kinds of improvements provide a high value in terms of improved seismic performance and limited construction impacts.

Snoqualmie Valley School District May 2013 Mount Si High School Building Assessment 1

1.0 Introduction This report presents the findings of the ASCE 31-03 Tier 1 seismic assessment performed by Reid Middleton, Inc., on Mount Si High School. This seismic assessment was performed to identify potential seismic deficiencies based on the Life Safety (LS) performance level and, where deficiencies were noted, to provide recommendations regarding more detailed seismic evaluations. In addition to the Tier 1 assessment, the condition of the school’s cafeteria area was observed to respond to a question about possible flood damage in that area.

1.1 Background A seismic assessment was performed to investigate potential structural seismic deficiencies. Mount Si High School was constructed in multiple phases over 50 years, with the original construction in 1951. Building systems used over the years of construction include concrete frames with concrete masonry unit (CMU) infill walls, precast concrete walls, and wood stud walls. The roof and floor framing typically consists of wood decking over wood joists or open web joists with glulam or steel beams. The typical foundation system consists of concrete grade beams spanning between concrete pile caps and piles.

A Tier 1 seismic assessment was performed in accordance with ASCE 31-03, Seismic Evaluation of Existing Buildings. The evaluation is based on structural record drawings provided by the owner and supplemented by a site visit on April 11, 2013, to perform limited observations of the existing condition of the structures. No material testing or removal of building finishes was performed. The Mount Si High School structure was evaluated for the expected structural performance using ASCE 31’s LS Performance Objective. This letter includes descriptions of the structural systems, identified deficiencies, and recommendations to perform subsequent evaluations based on the preliminary results of this assessment. Basic nonstructural and geotechnical checklists have also been completed. Completion of the nonstructural and geotechnical checklists was outside the project scope. This report addresses the main building structure; outbuildings, such as portables, the generator enclosure, and the greenhouse, were not reviewed.

Several areas of the main school building were excluded from the scope of this review. These include the Wildcat Court, the stadium bleachers, and the gymnasium areas. Record drawings provided by the district indicate that each of these areas were constructed or seismically improved within the last 10 years. Building codes used during that timeframe are similar to current building codes; buildings designed and permitted based on those codes typically have seismic force-resisting systems that are similar to those required today. If the school district is concerned about the design or construction of these structures, more detailed analysis or testing would be required.

We understand from the school district that seismic improvements were made to Rooms 315, 316, 319, 320, 321, and 322 following the February 28, 2001 Nisqually Earthquake. No records were available to establish the scope of the improvements and site observations were not able to confirm the extents of the work. For that reason, this area of the building was reviewed in a similar manner to the portions of the building that did not have improvements within the last 10 years.


1.2 Criteria The current standard for the seismic evaluation of existing buildings is the ASCE Standard 31-03, Seismic Evaluation of Existing Buildings (ASCE 31). ASCE 31 is a screening and evaluation document used to identify potential seismic deficiencies that may require additional evaluation or hazard mitigation. The document presents a three-tiered review process implemented by following a series of checklists and “quick check” calculations. Each successive tier is designed to perform an increasingly detailed evaluation for seismic deficiencies identified in previous tiers.

Tier 1 checklists screen for potential seismic deficiencies by comparing the lateral system and details of the structure with configurations that have historically caused poor seismic performance in similar buildings. Tier 1 includes basic analyses for primary components of the lateral system, such as columns, walls, frames, beams, and connections. Tier 2 provides more detailed evaluation and analysis to review potential deficiencies identified in the Tier 1 review. Tier 3 involves an even more detailed analysis of the seismic demand and capacity of each structural component. This report presents the findings for a Tier 1 assessment only.

Additional background information about the ASCE 31 seismic assessment methodology is included in Appendix A.


2.0 Findings 2.1 Structural Systems Mount Si High School is a complex building that has been constructed and revised over numerous phases. Dates of construction range from the original 1950s two-story structure to work completed within the last 10 years. Some areas, such as the Library and Commons areas, experienced partial demolition and reconstruction of previous structures to attain their current configuration. Many pre-1990s areas were heavily modified, including major structural revisions, during a 1990s modernization project. Review of the building’s record drawings requires considerable care to understand the current configuration and how it has been created over the previous decades.

Figure 1 shows the different eras of construction of Mount Si High School.

Figure 1. Mount Si High School Construction Era Key Plan.


Table 1 summarizes the structural systems of the different areas of the high school shown in Figure 1.

Table 1. Building Structural Systems.

Structural System Description

Low and High Roofs

Rooms 101 and 128–130: 5/8-inch plywood over wood joists supported on wood glulam beams, concrete columns, and precast concrete walls.

Rooms 103–109, Rooms 201-208, and corridors: 3/8-inch plywood on 1-inch diagonal sheathing over wood joists supported by wood glulam beams and wood posts, and concrete columns, beams, and walls. CMU infill walls are present in some original window locations.

Rooms 124-127: 5/8-inch plywood over open web joists supported on steel beams, bearing on steel posts, exterior precast concrete walls, and interior wood stud walls.

Rooms 300-314 and corridors: 3/4-inch plywood deck over open web joists supported by wood glulam beams and wood stud walls.

Rooms 315-322: 2-inch tongue and groove decking over wood purlins supported on steel beams bearing on CMU walls and pilasters.

Room 323: 1/2-inch PetriCal panels supported by open web steel joists spanning between CMU walls.

Library and Commons: 3/4-inch plywood sheathing over open web joists spanning between wood stud walls and wood glulam supported by steel posts.

Auditorium: The high roof consists of 3/8-inch plywood over 2-inch tongue and groove decking supported by steel trusses with vertical and horizontal steel rod bracing. The steel trusses span between concrete walls and columns. The low roof consists of a concrete pan joist system spanning between concrete walls and beams. The 3/8-inch plywood and 1-inch diagonal sheathing over wood joists is supported by steel beams spanning between CMU walls and concrete beams.

Room 405: Concrete pan joist slab system supported on CMU walls and concrete columns. 1-inch diagonal sheathing over wood joists supported by steel beams spanning between concrete beams and steel posts.

Room 406: 5/8-inch plywood sheathing over wood joists spanning between wood stud walls.

2nd Floor 3/8-inch plywood on 1-inch diagonal sheathing over wood joists supported by wood glulam beams and wood posts, and concrete columns, beams, and walls. CMU infill walls are present in some original window locations.


Structural System

Description

1st Floor and Foundations

Rooms 101 and 128-130: Exterior precast concrete walls and steel posts bear on pile caps and piles. Interior wood stud walls bear on concrete grade beams spanning between concrete pile caps and piles.

Rooms 103-121: Columns and walls are supported on pile caps over concrete piles. Grade beams tie the pile caps together. The floor consists of a concrete slab on grade and elevated concrete slab in some areas.

Rooms 124-126: Exterior precast concrete walls span between concrete pile caps and piles. Interior steel posts bear on wood glulam beams spanning between concrete piles. Floor system consists of plywood sheathing over wood joists bearing on the wood glulam beams and exterior precast concrete walls.

Rooms 300-314: 3/4-inch plywood over open web joists supported on wood cripple walls and exterior concrete walls on continuous concrete footings.

Rooms 315-322: CMU pilasters and walls bear on concrete grade beams and spread footings. The floor system consists of a 3 ½-inch concrete slab on grade.

Room 323: CMU walls are supported on concrete grade beams that span between concrete piles.

Library and Commons: The floor system consists of 3/4-inch plywood sheathing over open web joists spanning between wood cripple walls and concrete grade beams. Wood cripple walls are supported on concrete grade beams spanning between pile caps and piles.

Auditorium and Room 405: CMU walls are supported on concrete grade beams spanning between concrete pile caps and piles. Floor system consists of a 3 ½-inch concrete slab on grade and open web joists.

Room 405: Open web joists are supported on concrete grade beams spanning between concrete pile caps and piles.

Room 406: Mechanical room floor framing consists of 2-inch tongue and groove deck over wood joists spanning between wood stud walls. The first floor wood stud walls are supported on concrete grade beams spanning between concrete pile caps and piles. The floor system consists of a 4-inch slab on grade.

Lateral System

The lateral system of the high school consists of wood shear walls and CMU and precast concrete walls with wood roof and floor diaphragms. Seismic loads are transferred to concrete grade beams spanning between concrete pile caps and piles.


2.2 Seismic Deficiencies Seismic deficiencies identified by the Tier 1 evaluation are summarized in Table 2.

Table 2. Building Seismic Deficiencies.

Deficiency Description

Adjacent Buildings

Joints between different eras of construction are typically less than 4 percent the height of the shorter building section.

Geometry & Mass

The second story of the early 1950s construction is significantly smaller in horizontal dimension than the first floor built at the same time.

Vertical Discontinuities

The shear walls of the penthouse built during the 1990s construction do not continue to the foundation system. These penthouse walls lack adequate connection to the floor system below to transfer seismic forces.

Proportions Numerous CMU infill walls that were constructed as part of the upgrades to the two-story building have a height-to-thickness ratio that exceeds the Tier 1 limit.

Openings at Shear Walls

Large openings in the diaphragm due to stairwells in the two-story building exceed 25 percent of the overall length of the adjacent shear walls.

Masonry Joints A long vertical crack was observed between the CMU wall and pilaster near Rooms 320 and 322.

Precast Concrete Walls

Diagonal cracks at corners of openings in the wall were observed on the exterior of the Auditorium.

Reinforcing Steel in CMU

The CMU walls near Rooms 316-322 do not appear to have horizontal reinforcing steel. It was observed, however, that during a future upgrade, steel tubes were added as strong-backing to the CMU walls.

Wall-to-Foundation Connection

Positive connections are not provided between the walls and foundations to transfer shear and overturning forces in many of the precast concrete and CMU walls.

Wall Anchorage

Additional investigation would be required to determine the adequacy of stiffness of the diaphragm connection to the walls.

Wood Ledgers The potential for cross-grain bending of the wood ledgers is present throughout the building.

Cross Ties In several locations, cross ties stop on either side of the corridor and are not continuous between exterior walls.


Deficiency Description

Unblocked Diaphragm

The roof diaphragm over Rooms 315-322 does not appear to be blocked and the spans of the diaphragm exceed the 40-foot limit in some areas.

Diaphragm Continuity

The roof height varies throughout the building, causing discontinuity in the roof diaphragm and limited ability to transfer seismic forces.

Other Diaphragms

The auto shop roof diaphragm consists of PetriCal panels. These panels may not have the ability to transfer lateral forces to the CMU walls.

Uplift at Pile Caps

There does not appear to be top reinforcement in the concrete pile caps and the piles do not appear to have adequate connection to the pile caps to transfer loads.

Coupling Beams

The structural drawings do not indicate that the horizontal wall elements have effective stirrups at many locations. Stirrups are required to have hooks at top and bottom to engage, which are not indicated in most wall panels.

2.3 Seismic Deficiency Discussion As shown in the table, a number of potential structural deficiencies were identified by the ASCE 31-03 Tier 1 analyses. These deficiencies pose varying levels of risk to the building. The risk posed by some deficiencies will depend on the specific level of seismic loading that occurs at the deficient location. For example, unblocked plywood diaphragms do have some capacity to resist seismic loading. The “Unblocked Diaphragm” deficiency notes that the diaphragm is longer than is typical for unblocked diaphragms and so may pose a higher-than-typical risk of overload during an earthquake. More detailed analysis would be required to assess whether each unblocked diaphragm location is overloaded based on the specific conditions of each area.

Other deficiencies are less likely to be set aside by more detailed analysis and are therefore more likely to pose a risk. These include deficient connections that may not provide a continuous load path for seismic forces in the building. These primary deficiencies for the high school include the following:

1. Lack of positive connections between the CMU or precast concrete wall panels and the foundations to resist overturning forces and transfer shear. This occurs in several elements of the 1950s and 1960s construction.

2. Potential deficiencies in the out-of-plane connections between the walls and the floor and roof diaphragms. This includes cross-grain bending issues in some ledger connections. This occurs at many floor and roof levels in the 1950s through 1970s construction. The floor level for 1990s construction should also be reviewed with detailed capacity analysis.


3. Lack of top reinforcing steel in the concrete pile caps to resist overturning forces. Lack of reinforcing tying the tops of the piles to the cap structure.

Figure 2 shows the areas affected by the deficiencies listed above.

Figure 2. Mount Si High School Deficiencies Key Plan.

The 1990s-era roof penthouse structure appears to lack sufficient connection to the roof and supporting structure below. This is not noted as a primary deficiency based on the localized nature of the deficiency; however, the localized aspect of this deficiency may also lend itself to mitigation that is limited in its potential construction disruption to other areas.

Some nonstructural deficiencies may also exist in the structure, such as missing independent support for some lights; bracing for hanging equipment, flexible pipe, and conduit couplings; and lateral restraint of tall office furnishings. Performing a nonstructural assessment was not included in the project scope; however, items noted above were observed at multiple locations throughout the building.

Costs for addressing these deficiencies cannot be determined accurately without additional assessment and design; however, a number of resources exist for rough, planning-level seismic improvement costs. The Federal Emergency Management Agency publication FEMA 156, Typical Costs for Seismic Rehabilitation of Existing Buildings, provides generalized costs for various building types. Applying cost escalation factors to account for inflation since the


publication was written, that publication suggests potential cost numbers around $30–$40 per square foot. Based on our experience on recent projects, this appears to be a reasonable range to use for initial planning.

2.4 Cafeteria Flooding Observations The cafeteria area was observed during our site visit. We understand that the cafeteria area has experienced minor flooding and that the district is concerned about potential damage to the structure. No water was observed during our site visit; however, school staff reported that past flooding in this area has consisted of water several inches deep across the cafeteria floor.

No slab or wall cracking or signs of uneven settlement were observed in this area. Based on the record drawings provided by the district, the floor in this area appears to consist of a structural slab supported by a pile foundation system. This system appears to be intended to address poor soil conditions at the site. Deep foundation systems are typically not sensitive to minor flooding. For this reason, the lack of observed damage appears to be reasonable.


3.0 Recommendations Mount Si High School does not meet the LS performance objective based on the ASCE 31-03 Tier 1 structural evaluation structural checklists. The structures may also have several nonstructural deficiencies. The deficiencies identified by the Tier 1 analysis appear to be typical of those found in buildings of the same era and construction type. Some deficiencies appear to have been addressed during an overall building upgrade performed in the early 1990s; however, many deficiencies still remain.

3.1 Options for Additional Analysis and Planning Additional structural evaluation is recommended to further investigate the identified deficiencies. As discussed in the Criteria section of this report, some potential deficiencies identified in a Tier 1 review may potentially be resolved through more detailed analysis. Based on the type of deficiencies identified, a Tier 3 analysis may be required to review the capacity of elements with potential deficiencies. The “Geometry & Mass” deficiency and the “Shear Wall Openings” deficiency are two that appear to have potential to be resolved through additional analysis.

Some of the deficiencies, however, are less likely to be resolved through additional analysis. These include the three primary deficiencies noted in the Seismic Deficiency Discussion section of this letter. Cross-grain bending in the ledgers of the floor-to-wall and roof-to-wall connections is a key example of a deficiency that will not be resolved by additional analysis. Wood ledgers that rely on cross-grain bending or tension have typically performed poorly in earthquakes. For this reason, the 2009 International Existing Building Code makes the following statement:

Wood ledgers, top plates, or framing shall not be used in cross-grain bending or cross-grain tension.

See Figure 3 for an example of cross-grain bending in wood ledgers (excerpted from ASCE 31-03), side-by-side with a ledger detail pulled from the 1977 Additions and Alterations drawings occurring at Room 323.


Figure 3. Wood Ledger Cross-Grain Bending Comparison.

Where potential deficiencies, such as cross-grain bending, are not resolved by the Tier 3 analysis, this analysis could be used to provide a starting point for conceptual design of seismic upgrades. Concept design sketches can be used to generate preliminary cost estimates and provide the school district with information about the areas likely to be affected by mitigation work.

Some of the identified potential deficiencies may require nondestructive and/or invasive testing to supplement the information provided in the record drawings. Further investigation may be necessary to verify construction and allow increases in the calculated framing capacities.

We understand that Snoqualmie Valley School District is considering future renovation, remodeling, and expansion options for Mount Si High School. These projects could provide an opportunity to include seismic improvements with reduced cost and disruption, as compared to a stand-alone seismic project. Seismic improvement work often involves removal and patching of finishes to allow access to structural elements. When seismic improvements are incorporated into projects that are intended to remove and replace existing building finishes, overall costs can be reduced. Likewise, many of the typical strategies to improve roof-to-wall connections involve nailing through the existing roof plywood. This requires penetration and patching of the roofing materials. This can be combined with a re-roofing project to eliminate the added patching costs. This strategy of combining seismic improvements with other planned capital improvement projects is discussed in the Federal Emergency Management Agency’s publication FEMA 395, Incremental Seismic Rehabilitation of School Buildings (K-12). FEMA 395 makes the following statement:

A program of incremental seismic rehabilitation is likely to be more affordable and less disruptive if specific increments of seismic rehabilitation are integrated with other maintenance and capital improvement projects that would be undertaken regardless of whether or not seismic issues were being addressed.

This appears to offer considerable support to the district, should the option to incrementally address seismic improvements be pursued.


3.2 Options for Limited Upgrades Deficient wall-to-diaphragm and wall-to-foundation connections are a high priority for mitigation. These are outlined as primary deficiencies 1 and 2 in the list above. These conditions can be resolved as part of a wider building improvement program or as parts of smaller projects. The wide variety of different construction types and connection details throughout the building, resulting from the many phases of construction performed over the previous 60 years, means that seismic improvement details for each area may be slightly different. Therefore, the benefit in doing all of the work at the same time is not as great as it would be in a more typical building.

If the school district does not pursue a broader renovation and seismic program, we recommend that upgrades to deficient wall-to-diaphragm and wall-to-foundation connections be included as part of localized renovation projects. This work typically involves drilling steel anchor bolts into the existing concrete and masonry walls. These anchors can be attached to the existing wood beams and joists through the use of light-gauge steel connectors to provide a seismic load path that does not depend on cross-grain bending. At the foundation level, anchors can be drilled into the foundations. Some portions of this work can be done by working around existing ceiling systems or working in crawl spaces during minor renovation and improvement projects. In other areas, however, removal and replacement of the ceiling systems or flooring would be required.

3.3 Seismic Upgrade Triggers As discussed above, we understand that Snoqualmie Valley School District is considering future renovation, remodeling, and expansion options for Mount Si High School. There are a variety of situations in which building improvement projects can trigger mandatory seismic upgrades. These are identified in Chapter 34 of the 2012 International Building Code. In general, these include:

1. Added seismic weight. Adding weight increases seismic loading on the building. New elements, such as ventilation equipment, mezzanines, and heavy finishes (e.g., brick cladding), can increase the building’s seismic loading. The building code limits this increase to 10 percent as compared to the building’s originally-constructed condition. Increases exceeding 10 percent require seismic improvements.

2. Reduced seismic capacity. Building renovation projects often involve removal of existing walls or cutting of holes in existing walls (e.g., new doorways). This can reduce the wall’s ability to resist seismic loading and consequently increase seismic loads on adjacent elements. As with the added seismic weight item above, increases in the seismic loading of any element by more than 10 percent will trigger seismic improvements.

These limitations should be considered in the planning for future building improvement projects. This may also be subject to changes in future building codes or based on future King County ordinances.


3.4 Cafeteria Flooding No damage due to flooding was visually observed. Based on the pile foundation system shown in the record drawings, it appears that this area should be moderately resistant to damage from minor flooding. Over the long term, however, repeated flooding could result in corrosion of the reinforcement in the slab and piles. If the school district is concerned about this area, or if flooding recurs, the pile caps and slab structure could be observed. This would require access to the underside of the slab, which may require limited cutting and patching. Signs of distress in the slab, such as deflection or cracking in adjacent walls, could indicate that corrosion is taking place. If these occur, further investigation would be advisable.


4.0 Limitations The professional services described in this report were performed based on available record drawing information and limited visual observation of the structure. No destructive testing was performed to qualify as-built conditions or verify the quality of materials and workmanship. No other warranty is made as to the professional advice included in this report. This report provides an overview of potential seismic deficiencies in the building and does not address programming and planning issues. This report has been prepared for the exclusive use of Snoqualmie Valley School District and is not intended for use by other parties, as it may not contain sufficient information for purposes of other parties or their uses.

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APPENDIX A

Performance-Based Earthquake Engineering (PBEE)

Mount Si High School Building Assessment May 2013 Performance-Based Earthquake Engineering A-1

A Performance-Based Earthquake Engineering The seismic evaluation is based on performance-based earthquake engineering (PBEE) guidelines presented in ASCE 31-03 Seismic Evaluation of Existing Buildings (American Society of Civil Engineers, 2002). This section includes general background information on PBEE and an overview of seismic rehabilitation objectives, building performance levels, and seismic evaluation and rehabilitation procedures. Background Seismic analysis and building design has traditionally focused on one performance level – reducing the risk of life loss in the design earthquake. The concept of designing essential facilities that are needed immediately after an earthquake evolved after hospitals and other critical facilities were damaged in the 1971 San Fernando, California earthquake. This concept is balanced by the recognition that the cost of rehabilitating existing buildings to higher levels of seismic performance may be onerous to stakeholders and policy makers. In 1991, a comprehensive program was started in cooperation with FEMA to develop guidelines tailored to address this variation of performance levels. The first formal applications of performance-based evaluation and design guidelines were FEMA 310 Handbook for the Seismic Evaluation of Buildings – A Prestandard (1998) and FEMA 273 NEHRP Guidelines for the Seismic Rehabilitation of Buildings (1997). ASCE 31-02 and FEMA 356 superseded these documents. The new PBEE documents reflect advancements in technology and incorporate case studies and lessons learned from recent earthquakes. ASCE 31-03 and ASCE 41-06 provide criteria to be used in seismically evaluating and rehabilitating existing buildings, to attain a wide range of performance levels when subjected to earthquakes of varying severity. Using these criteria, relationships are established between structural response and performance-oriented descriptions such as Operational, Immediate Occupancy, Life Safety, and Collapse Prevention. As Figure 3-1 illustrates, each building performance description or objective directly relates to its expected post-earthquake damage state. Each damage state has readily identifiable consequences that include:

Cost – economic feasibility of restoring a facility to pre-earthquake condition. Public Safety – number of critical injuries and casualties to building occupants. Downtime – length of time the building is removed from service to make repairs.

Efforts by the Applied Technology Council (ATC), Pacific Earthquake Engineering Research Center (PEER), FEMA, and others are underway to quantify these estimated losses and allow stakeholders to make more informed decisions.


Figure 1. Estimated Performance-Related Consequences (Moehle, 2003)

Rehabilitation Objectives The seismic rehabilitation objective expresses the desired building behavior during an earthquake of projected severity (a design-level event). This objective consists of one or more goals, each with a target building performance level and corresponding earthquake hazard level. The four defined levels of building performance are Operational (OP), Immediate Occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). Common probabilistic earthquake hazard levels and their corresponding mean return periods follow. Table 1. Probabilistic Earthquake Hazard Levels and Return Period

Earthquake Hazard Level Probability of Exceedance in 50 Years

Mean Return Period (Years)

50% / 50-year 50 percent 72 20% / 50-year 20 percent 225

BSE-1 (10% / 50-year) 10 percent 474 BSE-2 (2% / 50-year) 2 percent 2,475

For each building, a decision must be made on the acceptable behavior for different seismic hazard levels. This decision must be balanced with the cost of rehabilitating the structure to obtain that behavior. Figure 2 presents the schematic relationship between different rehabilitation objectives and probable program cost.


Figure 2. Surface Matrix of Rehabilitation Objectives (FEMA, 1997) The “baseline” performance level for a standard building is referred to as the Basic Safety Objective (BSO). The BSO is defined as providing Collapse Prevention performance at the 2% / 50-year event and Life Safety performance at the 10-percent probability of exceedance in a 50-year event (10% / 50). Higher (enhanced) or lower (limited) objectives may be selected based on the facility's essential nature, its expected remaining life, and the associated cost and feasibility. The rehabilitation objective selected as a basis for design determines the benefit to be obtained in terms of improved safety, reduction in property damage, and interruption of use in the event of future earthquakes. Building Performance Levels The terminology used for target building performance levels is intended to represent design goals. These target levels are discrete damage states selected from the infinite spectrum of damage states that a building could experience during an earthquake. Because actual ground motion is seldom comparable to that used for design, the selected damage state may only determine relative performance during most events. Even given a ground motion similar to that used in design, variations from stated performance objectives should be expected. Variations in actual performance could be associated with the following:

Differences in the level of workmanship Variations in actual material strengths Deterioration of materials Unknown geometry and sizes of existing members


Differences in assumed and actual live loads in the building at the time of the earthquake Influence of nonstructural components Variations in response of soils beneath the building

Building performance is a combination of the performance of structural and nonstructural components. Structural performance is related to the amount of lateral deformation or drift of the structure and its capacity or ability to deform. In ASCE 31-03 and ASCE 41-06, it is intended that structures meeting Life Safety performance will be able to experience at least 33 percent greater lateral deformation before failure of primary elements. This equates to a safety factor of 1.33 against collapse. In the design of new buildings, somewhat better performance is expected, since structures are designed with an approximate 1.5-margin against collapse.

Figure 3. Building Performance Levels

Mitigation of nonstructural seismic hazards is a complex issue that is addressed independently in the evaluation and rehabilitation guidelines. Many nonstructural components, if adequately secured to a structure, are seismically rugged. However, mitigation of some nonstructural hazards (e.g., bracing for mechanical and electrical components within suspended ceiling systems, or the improvement of ceiling systems themselves) can result in extensive disruption of occupancy and can also be costly to repair or replace post earthquake. Due to these complexities and required coordination with other disciplines (e.g., architect, mechanical engineer, electrical engineer, hazardous materials engineer), nonstructural seismic performance has not been addressed in this initial evaluation. The owner, with assistance from the design team, will select a nonstructural performance level during the rehabilitation design process that considers the cost and benefit of this type of mitigation. Table 2 summarizes the approximate levels of structural and nonstructural damage that may be expected of buildings rehabilitated to the defined levels.


Table 2. Damage Control and Building Performance Levels (FEMA, 2000)

Building Performance Levels

Collapse

Prevention Life Safety

Immediate Occupancy

Operational

Overall Damage Severe Moderate Light Very Light

Permanent Drift Large: 1% to 5%. Some: 0.3% to 1%. Negligible. Same as Immediate Occupancy.

Remaining Strength and Stiffness after Earthquake

Little: Gravity system (columns and walls) functions, but building is near collapse.

Some: Gravity system functions, but building may be beyond economical repair.

Substantial: Minor cracking of structural elements.

Same as Immediate Occupancy.

Examples of Damage to Concrete Framing

Extensive cracking and spalling of concrete members. Crack widths greater than 1/4 inch.

Extensive cracking and spalling of concrete. Crack widths typically less than 1/4 inch and less than 1/8 inch in columns and joints.

Crack widths typically less than 1/8 inch and less than 1/16 inch in columns and joints.


Examples of Damage to Steel Framing

Extensive yielding and buckling of steel members. Significant connection failures.

Local buckling of steel beams and braces. Moderate amount of connection failures.

Minor deformation of steel members. No connection failures.


Other General Description

Structure likely not repairable or safe for reoccupancy due to potential collapse in aftershock.

Repair may be possible but may not be economically feasible. Repairs may be required prior to reoccupancy.

Minor repairs may be required, but building is safe to occupy.


Nonstructural Components

Extensive damage. Some exits blocked. Infills and unbraced parapets failed or at incipient failure.

Falling hazards mitigated but many architectural, mechanical, and electrical systems are damaged.

Minor cracking of facades, partitions, and ceilings. Equipment and contents generally secure but may not operate due to lack of utilities.

Negligible damage. All systems important to normal operation functional. Power and other utilities available, possibly from standby sources.

Comparison with New Building Design

Significantly more damage and greater risk.

Somewhat more damage and slightly higher risk.

Much less damage and lower risk.

Much less damage and lower risk.


Seismic Evaluation Procedure ASCE 31-03 provides a three-tiered evaluation procedure using performance-based criteria. Figure 3-4 shows the seismic evaluation process, which consists of three tiers: the Screening Phase (Tier 1), Evaluation Phase (Tier 2), and Detailed Evaluation Phase (Tier 3). A summary of each phase is provided.

Figure 4. Flow Chart and Description of ASCE 31 Seismic Evaluation Procedure

The Tier 3 detailed evaluation references and utilizes rehabilitation design criteria such as ASCE 41-06. Since ASCE 31-03 is an evaluation standard, it is written to accept greater damage levels within each performance level than permitted by retrofit design standards. This is consistent with the historic practice of evaluating existing buildings for slightly lower criteria than those used for design. ASCE 31-03 quantifies this difference by using a 0.75 reduction factor on demands when performing a Tier 3 evaluation. This essentially lowers the reliability of achieving the selected performance level from about 90 percent to 60 percent. This practice generally minimizes the need to rehabilitate structures with relatively modest deficiencies relative to the desired performance level.


Seismic Rehabilitation Procedure If seismic deficiencies are identified during the evaluation process, the owner and design team should review all initial conditions before proceeding with hazard mitigation. Many conditions may affect the rehabilitation design significantly, including the results of the seismic evaluation and seismic hazard study, building use and occupancy requirements, the presence of hazardous materials, and other anticipated building remodeling. The basic process for performance-based rehabilitation design is illustrated in Figure 3-5.

Figure 5. Seismic Rehabilitation Flow Diagram Following the review of initial conditions, concept designs may be performed in order to develop rough opinions of probable construction costs for one or more performance objectives. The owner and design team can then develop a rehabilitation strategy considering the associated costs and feasibility. Schematic and final design can then proceed through an iterative process until verification of acceptable building performance is obtained.

APPENDIX B

ASCE 31-03 Tier 1 Checklists

Basic Structural Checklist For Building Type C3A: Concrete Frames With Infill Masonry Shear Walls And Flexible Diaphragms

Mount Si High School – Math Building May, 2013 Seismic Evaluation - page 1 -

This Basic Structural Checklist shall be completed where required by Table 3-2. Each of the evaluation statements on this checklist shall be marked Compliant (C), Non-compliant (NC), or Not Applicable (N/A) for a Tier 1 evaluation. Compliant statements identify issues that are acceptable according to the criteria of this standard, while non-compliant statements identify issues that require further investigation. Certain statements may not apply to the buildings being evaluated. For non-compliant evaluation statements, the design professional may choose to conduct further investigation using the corresponding Tier 2 Evaluation procedure; corresponding section numbers are in parentheses following each evaluation statement.

Building System

C NC N/A EVALUATION STATEMENT COMMENT

X LOAD PATH: The structure shall contain a minimum of one complete load path for Life Safety and Immediate Occupancy for seismic force effects from any horizontal direction that serves to transfer the inertial forces from the mass to the foundation. (Tier 2: Sec. 4.3.1.1)

X ADJACENT BUILDINGS: The clear distance between the building being evaluated and any adjacent building shall be greater than 4 percent of the height of the shorter building for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.1.2)

3” clearance.

X MEZZANINES: Interior mezzanine levels shall be braced independently from the main structure, or shall be anchored to the lateral-force-resisting elements of the main structure. (Tier 2: Sec. 4.3.1.3)

X WEAK STORY: The strength of the lateral-force-resisting system in any story shall not be less than 80 percent of the strength in an adjacent story, above or below, for Life-Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.1)

X SOFT STORY: The stiffness of the lateral-force-resisting system in any story shall not be less than 70 percent of the lateral-force-system stiffness in an adjacent story above or below, or less than 80 percent of the average lateral-resisting-system stiffness of the three stories above or below for Life-Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.2)

X GEOMETRY: There shall be no changes in horizontal dimension of the lateral-force-resisting system of more than 30 percent in a story relative to adjacent stories for Life Safety and Immediate Occupancy, excluding one-story penthouses and mezzanines. (Tier 2: Sec. 4.3.2.3)

Based on the one-story section being much larger than the second story.

X VERTICAL DISCONTINUITIES: All vertical elements in the lateral-force-resisting system shall be continuous to the foundation. (Tier 2: Sec. 4.3.2.4)

X MASS: There shall be no change in effective mass more than 50 percent from one story to the next for Life Safety and Immediate Occupancy. Light roofs, penthouses, and mezzanines need not be considered. (Tier 2: Sec. 4.3.2.5)



X DETERIORATION OF WOOD: There shall be no signs of decay, shrinkage, splitting, fire damage, or sagging in any wood member and none of the metal connection hardware shall be deteriorated, broken, or loose. (Tier 2: Sec. 4.3.3.1)

No deterioration of wood was observed.

X DETERIORATION OF CONCRETE: There shall be no visible deterioration of concrete or reinforcing steel in any of the vertical- or lateral-force-resisting system elements. (Tier 2: Sec. 4.3.3.4)

No deterioration of concrete was observed.

X MASONRY UNITS: There shall be no visible deterioration of masonry units. (Tier 2: Sec. 4.3.3.7)

No deterioration of masonry was observed.

X MASONRY JOINTS: The mortar shall not be easily scraped away from the joints by hand with a metal tool, and there shall be no areas of eroded mortar. (Tier 2: Sec. 4.3.3.8)

X CRACKS IN INFILL WALLS: There shall be no existing diagonal cracks in the infilled walls that extend throughout a panel greater than 1/8 inch for Life Safety and 1/16 inch for Immediate Occupancy, or out-of-plane offsets in the bed joint greater than 1/8 inch for Life Safety and 1/16 inch for Immediate Occupancy. (Tier 2: Sec. 4.3.3.12)

X CRACKS IN BOUNDARY COLUMNS: There shall be no existing cracks wider than 1/8 inch for Life Safety and 1/16 inch for Immediate Occupancy in concrete columns that encase masonry infills. (Tier 2: Sec. 4.3.3.13)

Lateral Force Resisting System


X REDUNDANCY: The number of lines of shear walls in each principal direction shall be greater than or equal to 2 for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.1.1)

X SHEAR STRESS CHECK: The shear stress in the reinforced masonry shear walls, calculated using the Quick Check procedure of Section 3.5.3.3, shall be less than 70 psi for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.4.1)

X SHEAR STRESS CHECK: The shear stress in the unreinforced masonry shear walls, calculated using the Quick Check procedure of Section 3.5.3.3, shall be less than 30 psi for clay units and 70 psi for concrete units for Life Safety and for Immediate Occupancy. (Tier 2: Sec. 4.4.2.5.1)

X WALL CONNECTIONS: Masonry shall be in full contact with frame for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.6.1)



Connections


X TRANSFER TO SHEAR WALLS: Diaphragms shall be connected for transfer of loads to the shear walls for Life Safety and the connections shall be able to develop the lesser of the shear strength of the walls for Immediate Occupancy. (Tier 2: Sec. 4.6.2.1)

X CONCRETE COLUMNS: All concrete columns shall be doweled into the foundation for Life Safety, and the dowels shall be able to develop the tensile capacity of reinforcement in columns of lateral-force-resisting system for Immediate Occupancy. (Tier 2: Sec. 4.6.3.2)

Supplemental Structural Checklist For Building Type C3A: Concrete Frames With Infill Masonry Shear Walls And Flexible Diaphragms


This Supplemental Structural Checklist shall be completed where required by Table 3-2. The Basic Structural Checklist shall be completed prior to completing this Supplemental Structural Checklist.



X REINFORCING AT OPENINGS: All wall openings that interrupt rebar shall have trim reinforcement on all sides. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.4.3)

X PROPORTIONS: The height-to-thickness ratio of the infill walls at each story shall be less than 9 for Life Safety in levels of high seismicity, 13 for Immediate Occupancy in levels of moderate seismicity, and 8 for Immediate Occupancy in levels of high seismicity. (Tier 2: Sec. 4.4.2.6.2)

Numerous infill walls have ratios greater than 9.

X SOLID WALLS: The infill walls shall not be of cavity construction. (Tier 2: Sec. 4.4.2.6.3)

X INFILL WALLS: The infill walls shall be continuous to the soffits of the frame beams and to the columns to either side. (Tier 2: Sec. 4.4.2.6.4)

Diaphragms


X DIAPHRAGM CONTINUITY: The diaphragms shall not be composed of split-level floors and shall not have expansion joints. (Tier 2: Sec. 4.5.1.1)

X CROSS TIES: There shall be continuous cross ties between diaphragm chords. (Tier 2: Sec. 4.5.1.2)

Cross ties stop at either side of the corridor.

X OPENINGS AT SHEAR WALLS: Diaphragm openings immediately adjacent to the shear walls shall be less than 25 percent of the wall length for Life Safety and 15 percent of the wall length for Immediate Occupancy. (Tier 2: Sec. 4.5.1.4)

X OPENINGS AT EXTERIOR MASONRY SHEAR WALLS: Diaphragm openings immediately adjacent to exterior masonry shear walls shall not be greater than 8 feet long for Life Safety and 4 feet long for Immediate Occupancy. (Tier 2: 4.5.1.6)

X PLAN IRREGULARITIES: There shall be tensile capacity to develop the strength of the diaphragm at re-entrant corners or other locations of plan irregularities. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.7)

X DIAPHRAGM REINFORCEMENT AT OPENINGS: There shall be reinforcing around all diaphragm openings larger than 50 percent of the building width in either major plan dimension. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.8)

Supplemental Structural Checklist For Building Type C3A: Concrete Frames With Infill Masonry Shear Walls And Flexible Diaphragms


X STRAIGHT SHEATHING: All straight sheathed diaphragms shall have aspect ratios of less than 1-to-2 for Life Safety and 1-to-1 for Immediate Occupancy in the direction being considered. (Tier 2: Sec. 4.5.2.1)

Plywood sheathing was added in 1990.

X SPANS: All wood diaphragms with spans greater than 24 feet for Life Safety and 12 feet for Immediate Occupancy shall consist of wood structural panels or diagonal sheathing. (Tier 2: Sec. 4.5.2.2)

Plywood sheathing was added in 1990.

X UNBLOCKED DIAPHRAGMS: All diagonally sheathed or unblocked wood structural panel diaphragms shall have horizontal spans less than 40 feet for Life Safety and 25 feet for Immediate Occupancy and shall have aspect ratios less than or equal to 4-to-1 for Life Safety and 3-to-1 for Immediate Occupancy. (Tier 2: Sec. 4.5.2.3)

X NON-CONCRETE FILLED DIAPHRAGMS: Untopped metal deck diaphragms or metal deck diaphragms with fill other than concrete shall consist of horizontal spans less than 40 feet and shall have and shall have span/depth rations less than 4-to-1. This statement shall apply to Immediate occupancy Performance Level only. (Tier 2: Sec. 4.5.3.1)

X OTHER DIAPHRAGMS: The diaphragms shall not consist of a system other than wood, metal deck, concrete, or horizontal bracing. (Tier 2: Sec. 4.5.7.1)

Connections


X STIFFNESS OF WALL ANCHORS: Anchors of concrete or masonry walls to wood structural elements shall be installed taut and shall be stiff enough to limit the relative moment between the wall and the diaphragm to no greater than 1/8 inch prior to engagement of the anchors. (Tier 2: Sec. 4.6.1.4)

Additional investigation is required to determine the stiffness of the wall anchors.

X UPLIFT AT PILE CAPS: Pile caps shall have top reinforcement and piles shall be anchored to the pile caps for Life Safety, and the pile cap reinforcement and pile anchorage shall be able to develop the tensile capacity of the piles for Immediate Occupancy. (Tier 2: Sec. 4.6.3.10)

Top steel not shown in record drawings.

Basic Structural Checklist for Building Type W2: Wood Frames, Commercial And Industrial

Mount Si High School – 1990 Addition May, 2013 Seismic Evaluation - page 1 -


Building System





X SOFT STORY: The stiffness of the lateral-force-resisting system in any story shall not be less than 70 percent of the lateral-force-resisting system stiffness in an adjacent story above or below, or less than 80 percent of the average lateral-force-resisting system stiffness of the three stories above or below for Life-Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.2)



Penthouse shear walls are not continuous to foundation.


X DETERIORATION OF WOOD: There shall be no signs of decay, shrinkage, splitting, fire damage, or sagging in any of the wood members, and none of the metal connection hardware shall be deteriorated, broken, or loose. (Tier 2: Sec. 4.3.3.1)




X WOOD STRUCTURAL PANEL SHEAR WALL FASTENERS: There shall be no more than 15 percent of inadequate fastening such as overdriven fasteners, omitted blocking, excessive fastening spacing, or inadequate edge distance. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.3.3.2)




X SHEAR STRESS CHECK: The shear stress in the shear walls, calculated using the Quick Check procedure in Section 3.5.3.3, shall be less than the following values for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.7.1) Structural panel sheathing: 1000 plf Diagonal sheathing: 700 plf Straight sheathing: 100 plf All other conditions: 100 plf

X STUCCO (EXTERIOR PLASTER) SHEAR WALLS: Multi-story buildings shall not rely on exterior stucco walls as the primary lateral-force-resisting system. (Tier 2: Sec. 4.4.2.7.2)

X GYPSUM WALLBOARD OR PLASTER SHEAR WALLS: Interior plaster or gypsum wallboard shall not be used as shear walls on buildings over one story in height with the exception of the uppermost level of a multi-story building. (Tier 2: Sec. 4.4.2.7.3)

X NARRROW WOOD SHEAR WALLS: Narrow wood shear walls with an aspect ratio greater than 2-to-1 for Life Safety and 1.5-to-1 for Immediate Occupancy shall not be used to resist lateral forces developed in the building in levels of moderate and high seismicity. Narrow wood shear walls with an aspect ratio greater than 2-to-1 for Immediate Occupancy shall not be used to resist lateral forces developed in the building in levels of low seismicity. (Tier 2: Sec. 4.4.2.7.4)

X WALLS CONNECTED THROUGH FLOORS: Shear walls shall have interconnection between stories to transfer overturning and shear forces through the floor. (Tier 2: Sec. 4.4.2.7.5)

Penthouse shear wall connections are not adequate.

X HILLSIDE SITE: For structures that are taller on at least one side by more than one-half story due to a sloping site, all shear walls on the downhill slope shall have an aspect ratio less than 1-to-1 for Life Safety and 1-to-2 for Immediate Occupancy. (Tier 2: Sec. 4.4.2.7.6)

X CRIPPLE WALLS: Cripple walls below the first-floor-level shear walls shall be braced to the foundation with wood structural panels. (Tier 2: Sec. 4.4.2.7.7)



X OPENINGS: Walls with openings greater than 80 percent of the length shall be braced with wood structural panel shear walls with aspect ratios of not more than 1.5-to-1 or shall be supported by adjacent construction through positive ties capable of transferring the lateral forces. (Tier 2: Sec. 4.4.2.7.8)

Connections


X WOOD POSTS: There shall be a positive connection of wood posts to the foundation. (Tier 2: Sec. 4.6.3.3)

X WOOD SILLS: All wood sills shall be bolted to the foundation. (Tier 2: Sec. 4.6.3.4)

X GIRDER/COLUMN CONNECTION: There shall be a positive connection utilizing plates, connection hardware, or straps between the girder and the column support. (Tier 2: Sec. 4.6.4.1)

Supplemental Structural Checklist for Building Type W2: Wood Frames, Commercial And Industrial





X HOLD-DOWN ANCHORS: All shear walls shall have hold-down anchors constructed per acceptable construction practices, attached to the end studs. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.7.9)

Diaphragms



X ROOF CHORD CONTINUITY: All chord elements shall be continuous, regardless of changes in roof elevation. (Tier 2: Sec. 4.5.1.3)


X DIAPHRAGM REINFORCEMENT AT OPENINGS: There shall be reinforcing around all diaphragms openings larger than 50 percent of the building width in either major plan dimension. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.8)

X STRAIGHT SHEATHING: All straight sheathed diaphragms shall have aspect ratios less than 2-to-1 for Life Safety and 1-to-1 for Immediate Occupancy in the direction being considered. (Tier 2: Sec. 4.5.2.1)

X SPANS: All wood diaphragms with spans greater than 24 feet for Life Safety and 12 feet for Immediate Occupancy shall consist of wood structural panels or diagonal sheathing. Wood commercial and industrial buildings may have rod-braced systems. (Tier 2: Sec. 4.5.2.2)


X OTHER DIAPHRAGMS: The diaphragm shall not consist of a system other than wood, metal deck, concrete, or horizontal bracing. (Tier 2: Sec. 4.5.7.1)



Connections


X WOOD SILL BOLTS: Sill bolts shall be spaced at 6 feet or less for Life Safety and 4 feet or less for Immediate Occupancy, with proper edge and end distance provided for wood and concrete. (Tier 2: Sec. 4.6.3.9)

Basic Structural Checklist For Building Type RM1: Reinforced Masonry Bearing Walls With Flexible Diaphragms

Mount Si High School – Ind. Arts May, 2013 Seismic Evaluation - page 1 -


Building System




7” clearance


No Mezzanine Present

X WEAK STORY: The strength of the lateral-force-resisting system in any story shall not be less than 80 percent of the strength in an adjacent story, above or below, for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.1)

One Story Building

X SOFT STORY: The stiffness of the lateral-force-resisting system in any story shall not be less than 70 percent of the lateral-force-resisting system stiffness in an adjacent story above or below, or less than 80 percent of the average lateral-force-resisting system stiffness of the three stories above or below for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.2)

One Story Building


One Story Building



One Story Building




No deterioration of wood was observed during the site visit.


No cracks observed during site visit.


No cracks observed during site visit.

X REINFORCED MASONRY WALL CRACKS: All existing diagonal cracks in wall elements shall be less than 1/8 inch for Life Safety and 1/16 inch for Immediate Occupancy, shall not be concentrated in one location, and shall not form an X pattern. (Tier 2: Sec. 4.3.3.10)

No diagonal cracks observed.




There is only one line of shear walls in the N/S direction.


X REINFORCING STEEL: The total vertical and horizontal reinforcing steel ratio in reinforced masonry walls shall be greater than 0.002 for Life Safety and Immediate Occupancy of the wall with the minimum of 0.0007 for Life Safety and Immediate Occupancy in either of the two directions; the spacing of reinforcing steel shall be less than 48 inches for Life Safety and Immediate Occupancy; and all vertical bars shall extend to the top of the walls. (Tier 2: Sec. 4.4.2.4.2)

Both horizontal and vertical steel are spaced at 48 inches. 0.0008 horizontal steel, 0.0008 vertical steel.

Connections


X WALL ANCHORAGE: Exterior concrete or masonry walls that are dependent on the diaphragm for lateral support shall be anchored for out-of-plane forces at each diaphragm level with steel anchors, reinforcing dowels, or straps that are developed into the diaphragm. Connections shall have adequate strength to resist the connection force calculated in the Quick Check procedure of Section 3.5.3.7. (Tier 2: Sec. 4.6.1.1)

Anchors, straps or dowels are not provided.

X WOOD LEDGERS: The connection between the wall panels and the diaphragm shall not induce cross-grain bending or tension in the wood ledgers. (Tier 2: Sec. 4.6.1.2)

Cross-grain bending

X TRANSFER TO SHEAR WALLS: Diaphragms shall be connected for transfer of loads to the shear walls for Life Safety



and the connections shall be able to develop the lesser of the shear strength of the walls or diaphragms for Immediate Occupancy. (Tier 2: Sec. 4.6.2.1)

X FOUNDATION DOWELS: Wall reinforcement shall be doweled into the foundation for Life Safety, and the dowels shall be able to develop the lesser of the strength of the walls or the uplift capacity of the foundation for Immediate Occupancy. (Tier 2: Sec. 4.6.3.5)

Dowels are provided.


Supplemental Structural Checklist For Building Type RM1: Reinforced Masonry Bearing Wall With Flexible Diaphragms






X PROPORTIONS: The height-to-thickness ratio of the shear walls at each story shall be less than 30. This statement shall apply to the Immediate Occupancy Performance Level Only. (Tier 2: Sec. 4.4.2.4.4)

Diaphragms














Diaphragm consists of PetriCal material.

Connections



Additional investigation required.


Mount Si High School – Ind. Arts May, 2013 Seismic Evaluation - page 1-


Building System



ADJACENT BUILDINGS: The clear distance between the building being evaluated and any adjacent building shall be greater than 4 percent of the height of the shorter building for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.1.2)


No Mezzanine Present

X WEAK STORY: The strength of the lateral-force-resisting system in any story shall not be less than 80 percent of the strength in an adjacent story, above or below, for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.1)

One Story Building

X SOFT STORY: The stiffness of the lateral-force-resisting system in any story shall not be less than 70 percent of the lateral-force-resisting system stiffness in an adjacent story above or below, or less than 80 percent of the average lateral-force-resisting system stiffness of the three stories above or below for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.2)

One Story Building


One Story Building



One Story Building




No deterioration of wood was observed during the site visit.


No deterioration of CMU was observed.


Vertical Crack Near Rooms 320 and 322.

X REINFORCED MASONRY WALL CRACKS: All existing diagonal cracks in wall elements shall be less than 1/8 inch for Life Safety and 1/16 inch for Immediate Occupancy, shall not be concentrated in one location, and shall not form an X pattern. (Tier 2: Sec. 4.3.3.10)

No diagonal cracks observed.





X REINFORCING STEEL: The total vertical and horizontal reinforcing steel ratio in reinforced masonry walls shall be greater than 0.002 for Life Safety and Immediate Occupancy of the wall with the minimum of 0.0007 for Life Safety and Immediate Occupancy in either of the two directions; the spacing of reinforcing steel shall be less than 48 inches for Life Safety and Immediate Occupancy; and all vertical bars shall extend to the top of the walls. (Tier 2: Sec. 4.4.2.4.2)

No Vertical Reinforcement shown in the Record Drawings.

Connections


WALL ANCHORAGE: Exterior concrete or masonry walls that are dependent on the diaphragm for lateral support shall be anchored for out-of-plane forces at each diaphragm level with steel anchors, reinforcing dowels, or straps that are developed into the diaphragm. Connections shall have adequate strength to resist the connection force calculated in the Quick Check procedure of Section 3.5.3.7. (Tier 2: Sec. 4.6.1.1)


X TRANSFER TO SHEAR WALLS: Diaphragms shall be connected for transfer of loads to the shear walls for Life Safety



and the connections shall be able to develop the lesser of the shear strength of the walls or diaphragms for Immediate Occupancy. (Tier 2: Sec. 4.6.2.1)

X FOUNDATION DOWELS: Wall reinforcement shall be doweled into the foundation for Life Safety, and the dowels shall be able to develop the lesser of the strength of the walls or the uplift capacity of the foundation for Immediate Occupancy. (Tier 2: Sec. 4.6.3.5)

Record Drawings do not show vertical wall reinforcement doweling into foundation.








X PROPORTIONS: The height-to-thickness ratio of the shear walls at each story shall be less than 30. This statement shall apply to the Immediate Occupancy Performance Level Only. (Tier 2: Sec. 4.4.2.4.4)

Diaphragms


CROSS TIES: There shall be continuous cross ties between diaphragm chords. (Tier 2: Sec. 4.5.1.2)






Plywood was added in 1990.


Plywood was added in 1990.




Spans are greater than 40 feet.



Connections



More investigation is required.

Basic Structural Checklist For Building Type PC1: Precast/Tilt-Up Concrete Shear Walls With Flexible Diaphragms

Mount Si High School – Science Building May, 2013 Seismic Evaluation - page 1 -


Building System




3” clearance



X SOFT STORY: The stiffness of the lateral-force-resisting system in any story shall not be less than 70 percent of the lateral-force-system stiffness in an adjacent story above or below, or less than 80 percent of the average lateral-resisting-system stiffness of the three stories above or below for Life-Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.2)








X PRECAST CONCRETE WALLS: There shall be no visible deterioration of concrete or reinforcing steel or evidence of distress, especially at the connections. (Tier 2: Sec. 4.3.3.6)

No deterioration of precise concrete walls were observed.




SHEAR STRESS CHECK: The shear stress in the precast panels, calculated using the Quick Check procedure of Section 3.5.3.3 shall be less than 100 psi or 2fc

1/2 for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.3.1)

X REINFORCING STEEL: The ratio of reinforcing steel area to gross concrete area shall be greater than 0.0015 in the vertical direction and 0.0025 in the horizontal direction for Life Safety and Immediate Occupancy. The spacing in the reinforcing steel shall be equal to or less than 18 inches for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.3.2)

Connections


X WALL ANCHORAGE: Exterior concrete or masonry walls that are dependent on the diaphragm for lateral support shall be anchored for out-of-plane forces at each diaphragm level with steel anchors, reinforcing dowels, or straps that are developed into the diaphragm. Connections shall have adequate strength to resist the connection force calculated in the Quick Check procedure of Section 3.5.3.7. (Tier 2: Sec. 4.6.1.1)


X TRANSFER TO SHEAR WALLS: Diaphragms shall be connected for transfer of loads to the shear walls for Life Safety and the connections shall be able to develop the lesser of the shear strength of the walls or diaphragms for Immediate Occupancy. (Tier 2: Sec. 4.6.2.1)

X PRECAST WALL PANELS: Precast wall panels shall be doweled into the foundation for Life Safety and the connections shall be able to develop the strength of the walls for Immediate Occupancy. (Tier 2: Sec. 4.6.3.7)

Record drawings do not show doweling into the foundation.

X GIRDER/COLUMN CONNECTION: There shall be a positive connection utilizing plates, connection hardware, or straps



between the girder and the column support. (Tier 2: Sec. 4.6.4.1)

Supplemental Structural Checklist For Building Type PC1: Precast/Tilt-Up Concrete Shear Walls With Flexible Diaphragms





X COUPLING BEAMS: The stirrups in all coupling beams over means of egress shall be spaced at or less than d/2 and shall be anchored into the confined core of the beam with hooks of 135o or more for Life Safety. All coupling beams shall comply with the requirements above and shall have the capacity in shear to develop the uplift capacity of the adjacent wall for Immediate Occupancy. (Tier 2: Sec. 4.4.2.2.3)

X WALL OPENINGS: The total width of openings along any perimeter wall line shall constitute less than 75 percent of the length of any perimeter wall for Life Safety and 50 percent for Immediate Occupancy with the wall piers having aspect ratios of less than 2-to-1 for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.3.3)

X CORNER OPENINGS: Walls with openings at a building corner larger than the width of a typical panel shall be connected to the remainder of the wall with collector reinforcing. (Tier 2: Sec. 4.4.2.3.4)

X PANEL-TO-PANEL CONNECTIONS: Adjacent wall panels shall be interconnected to transfer overturning forces between panels by methods other than welded steel inserts. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.3.5)

X WALL THICKNESS: Thickness of bearing walls shall not be less than 1/25 the unsupported height or length, whichever is shorter, nor less than 4 inches. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.3.6)

Diaphragms





Supplemental Structural Checklist For Building Type PC1: Precast/Tilt-Up Concrete Shear Walls With Flexible Diaphragms




X UNBLOCKED DIAPHRAGMS: All diagonally sheathed or unblocked wood structural panel diaphragms shall have horizontal spans less than 40feet for Life Safety and 30 feet for Immediate Occupancy and shall have aspect ratios of less than or equal to 4-to-1 for Life Safety and 3-to-1 for Immediate Occupancy. (Tier 2: Sec. 4.5.2.3)


Connections


X PRECAST PANEL CONNECTIONS: There shall be at least two anchors from each precast wall panel into the diaphragm elements for Life Safety and the anchors shall be able to develop the strength of the panels for Immediate Occupancy. (Tier 2: Sec. 4.6.1.3)

X UPLIFT AT PILE CAPS: Pile caps shall have top reinforcement and piles shall be anchored to the pile caps for Life Safety, and the pile cap reinforcement and pile anchorage shall be able to develop the tensile capacity of the piles for Immediate Occupancy. (Tier 2: Sec. 4.6.3.10)

Top reinforcement not provided.

X GIRDERS: Girders supported by walls or pilasters shall have at least two ties securing the anchor bolts for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.6.4.2)


Mount Si High School – Music Building May, 2013 Seismic Evaluation - page 1 -


Building System





X SOFT STORY: The stiffness of the lateral-force-resisting system in any story shall not be less than 70 percent of the lateral-force-resisting system stiffness in an adjacent story above or below, or less than 80 percent of the average lateral-force-resisting system stiffness of the three stories above or below for Life-Safety and Immediate Occupancy. (Tier 2: Sec. 4.3.2.2)




X DETERIORATION OF WOOD: There shall be no signs of decay, shrinkage, splitting, fire damage, or sagging in any of the wood members, and none of the metal connection hardware shall be deteriorated, broken, or loose. (Tier 2: Sec. 4.3.3.1)

No deterioration was observed.



X WOOD STRUCTURAL PANEL SHEAR WALL FASTENERS: There shall be no more than 15 percent of inadequate fastening such as overdriven fasteners, omitted blocking, excessive fastening spacing, or inadequate edge distance. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.3.3.2)




X SHEAR STRESS CHECK: The shear stress in the shear walls, calculated using the Quick Check procedure in Section 3.5.3.3, shall be less than the following values for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.7.1) Structural panel sheathing: 1000 plf Diagonal sheathing: 700 plf Straight sheathing: 100 plf All other conditions: 100 plf

X STUCCO (EXTERIOR PLASTER) SHEAR WALLS: Multi-story buildings shall not rely on exterior stucco walls as the primary lateral-force-resisting system. (Tier 2: Sec. 4.4.2.7.2)

X GYPSUM WALLBOARD OR PLASTER SHEAR WALLS: Interior plaster or gypsum wallboard shall not be used as shear walls on buildings over one story in height with the exception of the uppermost level of a multi-story building. (Tier 2: Sec. 4.4.2.7.3)

X NARRROW WOOD SHEAR WALLS: Narrow wood shear walls with an aspect ratio greater than 2-to-1 for Life Safety and 1.5-to-1 for Immediate Occupancy shall not be used to resist lateral forces developed in the building in levels of moderate and high seismicity. Narrow wood shear walls with an aspect ratio greater than 2-to-1 for Immediate Occupancy shall not be used to resist lateral forces developed in the building in levels of low seismicity. (Tier 2: Sec. 4.4.2.7.4)

X WALLS CONNECTED THROUGH FLOORS: Shear walls shall have interconnection between stories to transfer overturning and shear forces through the floor. (Tier 2: Sec. 4.4.2.7.5)

X HILLSIDE SITE: For structures that are taller on at least one side by more than one-half story due to a sloping site, all shear walls on the downhill slope shall have an aspect ratio less than 1-to-1 for Life Safety and 1-to-2 for Immediate Occupancy. (Tier 2: Sec. 4.4.2.7.6)

X CRIPPLE WALLS: Cripple walls below the first-floor-level shear walls shall be braced to the foundation with wood structural panels. (Tier 2: Sec. 4.4.2.7.7)



X OPENINGS: Walls with openings greater than 80 percent of the length shall be braced with wood structural panel shear walls with aspect ratios of not more than 1.5-to-1 or shall be supported by adjacent construction through positive ties capable of transferring the lateral forces. (Tier 2: Sec. 4.4.2.7.8)

Connections


X WOOD POSTS: There shall be a positive connection of wood posts to the foundation. (Tier 2: Sec. 4.6.3.3)

X WOOD SILLS: All wood sills shall be bolted to the foundation. (Tier 2: Sec. 4.6.3.4)







X HOLD-DOWN ANCHORS: All shear walls shall have hold-down anchors constructed per acceptable construction practices, attached to the end studs. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.7.9)

Diaphragms



Not continuous at transition between sloped and flat roof.

X ROOF CHORD CONTINUITY: All chord elements shall be continuous, regardless of changes in roof elevation. (Tier 2: Sec. 4.5.1.3)


X DIAPHRAGM REINFORCEMENT AT OPENINGS: There shall be reinforcing around all diaphragms openings larger than 50 percent of the building width in either major plan dimension. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.8)

X STRAIGHT SHEATHING: All straight sheathed diaphragms shall have aspect ratios less than 2-to-1 for Life Safety and 1-to-1 for Immediate Occupancy in the direction being considered. (Tier 2: Sec. 4.5.2.1)

X SPANS: All wood diaphragms with spans greater than 24 feet for Life Safety and 12 feet for Immediate Occupancy shall consist of wood structural panels or diagonal sheathing. Wood commercial and industrial buildings may have rod-braced systems. (Tier 2: Sec. 4.5.2.2)





Connections


X WOOD SILL BOLTS: Sill bolts shall be spaced at 6 feet or less for Life Safety and 4 feet or less for Immediate Occupancy, with proper edge and end distance provided for wood and concrete. (Tier 2: Sec. 4.6.3.9)

APPENDIX C

Structural Calculations

MOUNT SI HIGH SCHOOL Snoqualmie Valley School District May 2013 Prepared for: Snoqualmie Valley School District

STRUCTURAL CALCULATIONS

Prepared By:

Paul Crocker, P.E., S.E. Suzie Brendle, P.E.

728 134th Street SW, Suite 200 Everett, WA 98204

425/741-3800 (Fax 425/741-3900) www.reidmiddleton.com

File No. 262013.026

Snoqualmie SD

728 134th Street SW - Suite 200 Mount Si High School Tier 1 Evaluation SRB

Everett, Washington 98204 Apr-13

Ph: 425 741-3800

Fax: 425 741-3900

I.D.: 1951-1952 Section

INPUT: 310 Ref.:

Building type: Table 2-2

Site class: 3.5.2.3.1

Mapped short period spectral accel.: SS = 1.19 g 3.5.2.3.1

Mapped spectral accel. @ T=1 s: S1 = 0.397 g 3.5.2.3.1

Velocity site coefficient: Fv = 1.6 Table 3-5

Acceleration site coefficient: Fa = 1.0 Table 3-6

Lateral system type: 3.5.2.4

Period coefficient: Ct = 0.020 3.5.2.4

Period coefficient: β = 0.750 3.5.2.4

Building height: hn = 27.67 ft 3.5.2.4

Number of stories: n = 2 Table 3-4

Modification factor: C = 1.0 Table 3-4

Building weight: W = 2258 k 3.5.2.1

PSEUDO LATERAL FORCE: 310 Ref.:Design short period spectral accel.: SDS = 2/3*Fa*SS = 0.812 g 3.5.2.3.1

Design 1 sec. period spectral accel.: SD1 = 2/3*Fv*S1 = 0.425 g 3.5.2.3.1

Region of seismicity is HIGH Table 2-1

ASCE 31-03 EARTHQUAKE FORCES

262013.026

D

C3A: Concrete frame with infill masonry shear walls

Steel CBF, Concrete/Masonry SW

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date

Region of seismicity is HIGH Table 2 1

Fundamental period: T = Ct*hnβ= 0.241 s 3.5.2.4

Mapped spectral acceleration: Sa = MIN(SD1/T,SDS) = 0.812 g 3.5.2.3.1

Pseudo lateral force: V = C*Sa*W = 0.812 W = 1834 k 3.5.2.1

FORCE DISTRIBUTION CALCULATIONS: 310 Ref.:Tier 1 story shear force: Vj = ΣFx see table 3.5.2.2

Tier 2 story force: Fx = wx*hxk/(wi*hi

k)*V = see table 3.5.2.2

k = IF(T=0.5,1,IF(T>2.5,2,1+(T-0.5)/2)) = 1.000 3.5.2.2

wi*hik = 3.5.2.2

Tier 2 diaphragm force: Fpx = wx/C*Σ Fi / Σ wi = see table 4.2.2.1.4

Story Story Story Story Total T1 Story T1 Story T2 Story T2 Diaph.

Number Name Weight Height Weight Shear Force Force Force

j wx hx Wj Vj Fj wx*hxk Fx Fpx

(k) (ft) (k) (k) (k) (k) (k)

2 Roof 528 27.67 528 695.4 695.4 14610 695.4 695.4

1 Low Rf/2 1730 13.83 2258 1834.3 1138.9 23926 1138.9 1405.4

38536

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: 1951-1952 Section


262013.026

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date

DESIGN RESPONSE SPECTRUM:

T Sa

(s) (g)

0.00 0.81

0.05 0.81

0.10 0.81

0.15 0.81

0.20 0.81

0.25 0.81

0.30 0.81

0.35 0.81

0.40 0.81

0.45 0.81

0.50 0.81

0.55 0.77

0 60 0 71

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90c

tra

l Ac

ce

lera

tio

n,

Sa

(g

)

Design Response Spectrum

0.60 0.71

0.65 0.65

0.70 0.61

0.75 0.57

0.80 0.53

0.85 0.50

0.90 0.47

0.95 0.45

1.00 0.43

1.10 0.39

1.20 0.35

1.30 0.33

1.40 0.30

1.50 0.28

1.60 0.27

1.70 0.25

1.80 0.24

1.90 0.22

2.00 0.21

2.25 0.19

2.50 0.17

2.75 0.15

3.00 0.14

0.00

0.10

0.0

0

0.2

5

0.5

0

0.7

5

1.0

0

1.2

5

1.5

0

1.7

5

2.0

0

2.2

5

2.5

0

2.7

5

3.0

0

Sp

ec

Period, T (s)

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Corridoor with Rooms 122 and 123

INPUT: 310 Ref.:










Building height: hn = 15 ft 3.5.2.4








262013.026

D

W2: Wood frame

Wood buildings

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date








k = IF(T=0.5,1,IF(T>2.5,2,1+(T-0.5)/2)) = 1.000 3.5.2.2

wi*hik = 3.5.2.2





(k) (ft) (k) (k) (k) (k) (k)

1 Roof 188 15 188 198.5 198.5 2820 198.5 152.7

2820

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Corridoor with Rooms 122 and 123


262013.026

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date


T Sa

(s) (g)

0.00 0.81

0.05 0.81

0.10 0.81

0.15 0.81

0.20 0.81

0.25 0.81

0.30 0.81

0.35 0.81

0.40 0.81

0.45 0.81

0.50 0.81

0.55 0.77

0 60 0 71

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90c

tra

l Ac

ce

lera

tio

n,

Sa

(g

)


0.60 0.71

0.65 0.65

0.70 0.61

0.75 0.57

0.80 0.53

0.85 0.50

0.90 0.47

0.95 0.45

1.00 0.43

1.10 0.39

1.20 0.35

1.30 0.33

1.40 0.30

1.50 0.28

1.60 0.27

1.70 0.25

1.80 0.24

1.90 0.22

2.00 0.21

2.25 0.19

2.50 0.17

2.75 0.15

3.00 0.14

0.00

0.10

0.0

0

0.2

5

0.5

0

0.7

5

1.0

0

1.2

5

1.5

0

1.7

5

2.0

0

2.2

5

2.5

0

2.7

5

3.0

0

Sp

ec

Period, T (s)

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Auto Shop

INPUT: 310 Ref.:










Building height: hn = 15.5 ft 3.5.2.4








262013.026

D

RM1: Reinforced masonry bearing walls with flexible diaphragms


Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date








k = IF(T=0.5,1,IF(T>2.5,2,1+(T-0.5)/2)) = 1.000 3.5.2.2

wi*hik = 3.5.2.2





(k) (ft) (k) (k) (k) (k) (k)

1 Roof 178 15.5 178 144.6 144.6 2759 144.6 144.6

2759

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Auto Shop


262013.026

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date


T Sa

(s) (g)

0.00 0.81

0.05 0.81

0.10 0.81

0.15 0.81

0.20 0.81

0.25 0.81

0.30 0.81

0.35 0.81

0.40 0.81

0.45 0.81

0.50 0.81

0.55 0.77

0 60 0 71

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90c

tra

l Ac

ce

lera

tio

n,

Sa

(g

)


0.60 0.71

0.65 0.65

0.70 0.61

0.75 0.57

0.80 0.53

0.85 0.50

0.90 0.47

0.95 0.45

1.00 0.43

1.10 0.39

1.20 0.35

1.30 0.33

1.40 0.30

1.50 0.28

1.60 0.27

1.70 0.25

1.80 0.24

1.90 0.22

2.00 0.21

2.25 0.19

2.50 0.17

2.75 0.15

3.00 0.14

0.00

0.10

0.0

0

0.2

5

0.5

0

0.7

5

1.0

0

1.2

5

1.5

0

1.7

5

2.0

0

2.2

5

2.5

0

2.7

5

3.0

0

Sp

ec

Period, T (s)

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Industrial Arts

INPUT: 310 Ref.:


















262013.026

D

RM1: Reinforced masonry bearing walls with flexible diaphragms


Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date








k = IF(T=0.5,1,IF(T>2.5,2,1+(T-0.5)/2)) = 1.000 3.5.2.2

wi*hik = 3.5.2.2





(k) (ft) (k) (k) (k) (k) (k)

1 Roof 573 16 573 465.5 465.5 9168 465.5 465.5

9168

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Industrial Arts


262013.026

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date


T Sa

(s) (g)

0.00 0.81

0.05 0.81

0.10 0.81

0.15 0.81

0.20 0.81

0.25 0.81

0.30 0.81

0.35 0.81

0.40 0.81

0.45 0.81

0.50 0.81

0.55 0.77

0 60 0 71

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90c

tra

l Ac

ce

lera

tio

n,

Sa

(g

)


0.60 0.71

0.65 0.65

0.70 0.61

0.75 0.57

0.80 0.53

0.85 0.50

0.90 0.47

0.95 0.45

1.00 0.43

1.10 0.39

1.20 0.35

1.30 0.33

1.40 0.30

1.50 0.28

1.60 0.27

1.70 0.25

1.80 0.24

1.90 0.22

2.00 0.21

2.25 0.19

2.50 0.17

2.75 0.15

3.00 0.14

0.00

0.10

0.0

0

0.2

5

0.5

0

0.7

5

1.0

0

1.2

5

1.5

0

1.7

5

2.0

0

2.2

5

2.5

0

2.7

5

3.0

0

Sp

ec

Period, T (s)

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Auditorium

INPUT: 310 Ref.:


















262013.026

D

PC1A: Precast/Tilt-up concrete shear walls


Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date








k = IF(T=0.5,1,IF(T>2.5,2,1+(T-0.5)/2)) = 1.000 3.5.2.2

wi*hik = 3.5.2.2





(k) (ft) (k) (k) (k) (k) (k)

2 Hi Roof 596 34 596 769.5 769.5 20264 769.5 641.2

1 Low Roof 465 15 1061 1034.3 264.9 6975 264.9 377.8

27239

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Auditorium


262013.026

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date


T Sa

(s) (g)

0.00 0.81

0.05 0.81

0.10 0.81

0.15 0.81

0.20 0.81

0.25 0.81

0.30 0.81

0.35 0.81

0.40 0.81

0.45 0.81

0.50 0.81

0.55 0.77

0 60 0 71

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90c

tra

l Ac

ce

lera

tio

n,

Sa

(g

)


0.60 0.71

0.65 0.65

0.70 0.61

0.75 0.57

0.80 0.53

0.85 0.50

0.90 0.47

0.95 0.45

1.00 0.43

1.10 0.39

1.20 0.35

1.30 0.33

1.40 0.30

1.50 0.28

1.60 0.27

1.70 0.25

1.80 0.24

1.90 0.22

2.00 0.21

2.25 0.19

2.50 0.17

2.75 0.15

3.00 0.14

0.00

0.10

0.0

0

0.2

5

0.5

0

0.7

5

1.0

0

1.2

5

1.5

0

1.7

5

2.0

0

2.2

5

2.5

0

2.7

5

3.0

0

Sp

ec

Period, T (s)

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Music Building

INPUT: 310 Ref.:


















262013.026

D

W2: Wood frame

Wood buildings

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date








k = IF(T=0.5,1,IF(T>2.5,2,1+(T-0.5)/2)) = 1.012 3.5.2.2

wi*hik = 3.5.2.2





(k) (ft) (k) (k) (k) (k) (k)

2 Roof 117 18 117 93.8 93.8 2181 93.8 85.2

1 Mezz 30 8 147 104.3 10.6 246 10.6 19.4

2428

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: Music Building


262013.026

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date


T Sa

(s) (g)

0.00 0.81

0.05 0.81

0.10 0.81

0.15 0.81

0.20 0.81

0.25 0.81

0.30 0.81

0.35 0.81

0.40 0.81

0.45 0.81

0.50 0.81

0.55 0.77

0 60 0 71

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90c

tra

l Ac

ce

lera

tio

n,

Sa

(g

)


0.60 0.71

0.65 0.65

0.70 0.61

0.75 0.57

0.80 0.53

0.85 0.50

0.90 0.47

0.95 0.45

1.00 0.43

1.10 0.39

1.20 0.35

1.30 0.33

1.40 0.30

1.50 0.28

1.60 0.27

1.70 0.25

1.80 0.24

1.90 0.22

2.00 0.21

2.25 0.19

2.50 0.17

2.75 0.15

3.00 0.14

0.00

0.10

0.0

0

0.2

5

0.5

0

0.7

5

1.0

0

1.2

5

1.5

0

1.7

5

2.0

0

2.2

5

2.5

0

2.7

5

3.0

0

Sp

ec

Period, T (s)

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: 1960s/1990 Classroom Additions

INPUT: 310 Ref.:


















262013.026

D

W2: Wood frame

Wood buildings

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date








k = IF(T=0.5,1,IF(T>2.5,2,1+(T-0.5)/2)) = 1.012 3.5.2.2

wi*hik = 3.5.2.2





(k) (ft) (k) (k) (k) (k) (k)

1 Roof 2588 18 2588 2727.4 2727.4 48251 2727.4 2098.0

48251

Snoqualmie SD



Ph: 425 741-3800

Fax: 425 741-3900

I.D.: 1960s/1990 Classroom Additions


262013.026

Client

Project

Project No.

Sheet of

Design by

Date

Checked by

Date


T Sa

(s) (g)

0.00 0.81

0.05 0.81

0.10 0.81

0.15 0.81

0.20 0.81

0.25 0.81

0.30 0.81

0.35 0.81

0.40 0.81

0.45 0.81

0.50 0.81

0.55 0.77

0 60 0 71

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90c

tra

l Ac

ce

lera

tio

n,

Sa

(g

)


0.60 0.71

0.65 0.65

0.70 0.61

0.75 0.57

0.80 0.53

0.85 0.50

0.90 0.47

0.95 0.45

1.00 0.43

1.10 0.39

1.20 0.35

1.30 0.33

1.40 0.30

1.50 0.28

1.60 0.27

1.70 0.25

1.80 0.24

1.90 0.22

2.00 0.21

2.25 0.19

2.50 0.17

2.75 0.15

3.00 0.14

0.00

0.10

0.0

0

0.2

5

0.5

0

0.7

5

1.0

0

1.2

5

1.5

0

1.7

5

2.0

0

2.2

5

2.5

0

2.7

5

3.0

0

Sp

ec

Period, T (s)

APPENDIX D

References/Glossary of Terms

Mount Si High School Building Assessment May 2013 References/Glossary of Terms D-1

D References/Glossary of Terms References ASCE/SEI 31-03, 2003, Seismic Evaluation of Existing Buildings, prepared by the Structural

Engineering Institute of the American Society of Civil Engineers, Reston, Virginia.

ASCE/SEI 41-06, 2007, Seismic Rehabilitation of Existing Buildings, prepared by the Structural

Engineering Institute of the American Society of Civil Engineers, Reston, Virginia. ATC-20, 1989, Procedures for Postearthquake Safety Evaluation of Buildings, prepared by the

Applied Technology Council for the California Office of Statewide Health Planning and Development and the Federal Emergency Management Agency, Redwood City, CA.

ATC-20-1, 2005, Field Manual: Postearthquake Safety Evaluation of Buildings, prepared by the

Applied Technology Council, Redwood City, CA. FEMA-155, 2002, Rapid Visual Screening of Buildings for Potential Seismic Hazards:

Supporting Documentation, 2E, prepared by the Applied Technology Council for the Federal Emergency Management Agency, Washington, D.C.

FEMA-156, 1994, Typical Costs for Seismic Rehabilitation of Existing Buildings, Volume 1 -

Summary, Second Edition prepared by the Hart Consultant Group, Inc. for the Federal Emergency Management Agency, Washington, D.C.

FEMA-273, 1997, NEHRP Guidelines for the Seismic Rehabilitation of Buildings, prepared by

the Building Seismic Safety Council for the Federal Emergency Management Agency, Washington, D.C.

FEMA-274, 1997 NEHRP Commentary for the Seismic Rehabilitation of Buildings, prepared by

the Building Seismic Safety Council for the Federal Emergency Management Agency, Washington, D.C.

FEMA-356, 2000, Prestandard and Commentary for the Seismic Rehabilitation of Buildings,

prepared by the American Society of Civil Engineers for the Federal Emergency Management Agency, Washington, D.C.

FEMA-395, 2003, Incremental Seismic Rehabilitation of School Buildings (K-12), prepared by

the Virginia Polytechnic Institute and State University for the Federal Emergency Management Agency, Washington, D.C.

FEMA-445, 2006, Next-Generation Performance-Based Seismic Design Guidelines Program

Plan for New and Existing Buildings, prepared by Applied Technology Council for Federal Emergency Management Agency, Washington, D.C.


IBC, 2006, International Building Code 2006, International Code Council, Falls Church, Virginia.

Moehle, J., 2003, “A Framework for Performance-Based Earthquake Engineering,” Proceedings

from ATC 15-9, 10th US-Japan Workshop on the Improvements of Structural Design and Construction Practices, Applied Technology Council, Makena, Hawaii.

Reconnaissance Report (SSRP-2001/02) of the February 28, 2001, Nisqually (Seattle-Olympia)

Earthquake prepared by University of California, San Diego; André Filiatrault, Chia-Ming Uang, Bryan Folz, Constantin Chrstopoulos, Kip Gatto; March 2001.


Glossary of Terms

ASCE: American Society of Civil Engineers

ATC: Applied Technology Council

Brace: A diagonally placed structural member that withstands tensions and compression loads, and typically stiffens a structural against lateral loads.

Braced Frame: A building frame consisting of beams, columns, and braces.

BSO: Basic Safety Objective

CMU: Concrete Masonry Unit

CP: Collapse-Prevention (Performance Level)

Cripple Wall: A wall that is less than full story height and usually occurs between the first floor and the foundations and is generally the weakest part of older buildings.

Collector: An element, typically horizontal, used to collect and distribute all loads applied from the diaphragm to columns and shear walls transferring loads to the foundation.

Diaphragm: Horizontal structural system used to transfer lateral loads to walls or frames. Floors and roofs typically act as diaphragms.

Dowel: Solid cylindrical rod used to pin components together.

Drag Strut: A member that transfers lateral force from one member to another member or element in the structural frame of a building.

FEMA : Federal Emergency Management Agency

Glulam: Glued laminated timber; A type of structural timber product composed of several layers of dimensioned lumber glued together.

GSF: Gross Square Footage

Hold Down: Steel device or hardware that is installed typically at the end of a wood shear wall. The hold downs provide uplift resistance against the overturning moment imposed on the wall due to loads applied at the top of the wall.

HSS: Hollow Steel Section; steel tubes with a square, rectangular, or circular shape.

Hurricane Ties: typically light-gauge steel hardware pieces that connect the joists to supporting beams or walls to reduce uplift forces caused by high winds.

IBC: International Building Code

IO: Immediate Occupancy (Performance Level)

Joist: Horizontal load bearing members that run from wall to wall, wall to beam, or beam to beam to support a ceiling, roof, or floor.

Knee Brace: A diagonal member for bracing the angle between two joined members, such as a column to roof beam.

Lateral Force-Resisting Element: Part of a building, such as a shear wall, designed and constructed to resist racking, overturning, and sliding resulting from wind or earthquake loading.

LEED: Leadership in Energy and Environmental Building Design


LFRS: Lateral Force-Resisting System

LS: Life Safety (Performance Level)

MCE: Maximum Considered Earthquake

Moment Frame: Beams and columns joined by a combination of welding and bolting used to prevent any change in angle between the beam and column; used to resist lateral loads through bending of the frame elements.

NEHRP: National Earthquake Hazards Reduction Program

OP: Operational (Performance Level)

Out-of-Plane Force: A load applied perpendicular to the plane of rotation.

PBEE: Performance-Based Earthquake Engineering

Pre-cast Concrete: A form of construction where concrete is cast in a reusable mold which is then cured in a controlled environment, transported to the construction site, and lifted into place.

Re-entrant Corner: Condition that exists when both sides of the building project beyond the corner by more than 15 percent of the respective plan dimensions of the structure.

Re-sheath: To install new wood sheathing, usually to strengthen a diaphragm.

RVSP: Rapid Visual Screening Procedure

Sister Stations: Two fire stations that are exactly the same with exception of their location.

Shear Wall: Wall designed to counter the effects of lateral loads (such as wind and earthquake loads) acting on a structure

Sheathing: A layer of boards or of other wood or fiber materials applied to wall studs, joists, or rafters of a building to strengthen the structure.

Shiplap: Wooden siding cut so that the edge of one board overlaps the one next to it in a flush joint finish.

Shotcrete: Mortar (usually concrete) conveyed through a hose and projected onto a surface. Shotcrete undergoes placement and compaction at the same time due to the force with which it is projected from the nozzle. It can be impacted onto any type or shape of surface, including vertical or overhead areas. Spread Footing: A wide, isolated foundation element usually made of reinforced concrete.

T1-11: A type of vertically grooved plywood siding.

TJI: Engineered wood I-joist typically used in floor or roof framing.

Topping Slab: An additional layer of concrete used to provide a level floor surface or to increase strength if reinforced properly.

Unreinforced Masonry: Individual units laid in and bound together by mortar and do not include any steel reinforcing.

Wall Anchorage: A fastener that attaches the wall to either the ceiling or the foundation in order to provide a path for loads to transfer though the building to the foundation.

Wall Tie: A type of anchor (usually a metal strap) used to secure facing to a backup wall or to connect the two wythes of a cavity wall.

Documents

Mount Si HS Building Assessment Report€¦ · and evaluation document used to identify potential seismic deficiencies that may require additional evaluation or hazard mitigation