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Tips, Techniques & Strategies

Quality Assurance for Structural

Engineering Firms

by Clifford Schwinger, P.E.The Harman Group, Structural Engineers

King of Prussia, Pa.

Structural Engineers Association of Ohio

Annual Conference Presentation

9/12/13

• Quality Assurance Programs

• Quality Assurance Review procedures,

tips and techniques.

What we’ll be covering*

The QA program documents procedures

and standards used to facilitate design and

to facilitate documentation of design.

Quality Assurance is a mindset.

The Quality Assurance Program • Better design

• Better drawings

• More efficient design process

• Fewer mistakes

• Fewer RFI’s / change orders

• Increased profit

Advantages of a QA Program

• Fast schedules

• More changes during design

• Less experienced engineers

detailing/coordinating projects

• Computer analysis

• Complex Codes

• RFI’s / Change Orders

• Lost art of structural drafting

• Communication issues

• The need to be proactive

Why is a QA Program important?

• A QA manager available to answer questions.

• A single QA review prior to drawings going out

for bid.

That process no longer works*

The QA program 20 years ago

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• Formal processes and procedures

• Ongoing QA

• Multiple formal QA reviews

Today’s QA process

• More efficient design process

• Less re7design

• More efficient QA review process

• Fewer mistakes on the contract documents

• Fewer RFI’s and change orders

• Better training process for young engineers

Advantages of a QA program

• Selection of structural system

• Analysis

• Design and detailing

• Documentation of design

• Construction Administration

QA program facilitates and monitors,

The Quality Assurance Program

Two useful publications

The QA program

CASE Document 962 D, A Guideline Addressing

Coordination and Completeness of Structural

Construction Documents, 2003, Council of American

Structural Engineers.

Contractor’s Guide to Change Orders, Andrew

Civitello, Jr., Second Edition, 2002, Prentice Hall

Who is responsible for Quality Assurance?

• Everyone

• The attitude, “He/she will find my mistakes when they

review the drawings” is unacceptable.

• The attitude, “I don’t make mistakes and I don’t need

anyone to review my drawings” is dangerous.

• A successful QA program requires teamwork and

communication.

• Asking questions should be encouraged.

The QA program

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QA Manager requirements:

• 15 years experience (minimum)

• Detail oriented

• Good communicator

• Not afraid of confrontation

The QA program

• Staff training

• Design standards

• CAD & BIM standards

• Project Delivery System

• Knowledge Base

• QA reviews / involvement of QA manager

The QA program

Components of a QA program

Formal training seminars on topics required to

provide engineers the skills and knowledge

needed to become more productive.

Mentoring of young engineers

Staff training

The QA program

Connection design

Slabs on metal deck

Joists

Window washing davits

AISC 360710

Lessons learned

Bracing

Diaphragm design

Communication skills

Structural drafting

Some lunchtime seminar topics

The QA program

Load Paths

Seismic design

Wind tunnel studies

Vibration

Expansion Joints

Concrete mix design

Post7installed anchors

Braced Frames

Shop drawing review

Validating computer analysis

In7house design guides, office standards

and checklists for all topics related to

structural design.

Design standards

The QA program

• CAD / drafting / detailing procedures

• Typical details

• “go7by” drawings

• BIM procedures & protocols

• Modeling standards

CAD & BIM standards

The QA program

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Checklists and procedures:

• Project startup

• Schematic design

• Design development

• Contract documents

• Construction Administration

Project Delivery System

The PDS is the roadmap that engineers follow to

successfully take a project from beginning to end.

The PDS eliminates re7invention of the wheel on

each project.

The QA program

Knowledge Base

• Server7based database of all knowledge

related to structural engineering.

• Similar to Wikipedia

• Contains knowledge – not just information

• Contains checklists, design guides,

seminar notes

The QA program

Involvement of QA manager

• Establishing and maintaining design and drafting

standards

• Answering technical questions

• Staff training

• Review of framing plans & details before going to CAD

• “Maintaining involvement and familiarity on all projects

(“Ongoing QA”) via scheduled meetings for all projects.

• Performing QA reviews

The QA program

Ongoing Quality Assurance

• Maintaining familiarity with all projects as

they progress through design

• Proactive approach to catch problems early

• Ongoing QA is key to enhancing efficiency &

productivity

The QA program

The Quality Assurance

Review

Strategies & tactics

In7house reviews conducted to verify that

design and documentation is in conformance

with procedures, practices and standards

mandated by the QA program.

Quality Assurance Reviews

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• Redundancy

• Monitor effectiveness of QA program

QA Reviews

Purpose of the QA review Ongoing QA makes QA reviews easier

• Catch mistakes before they get onto the

drawings

• Catch mistakes early when they are easy to fix

QA Reviews

• Foundation permit

• Concrete bid

• Steel bid

• Addendum issues

• “Issued For Construction”

QA Reviews

Typical QA review schedule

Best to do these reviews before the

drawings are issued – not after.

Look at:

• Big picture – load paths / framing efficiency

• Member sizes

• Critical connection details

• Constructability

QA Reviews

Primary strategic goal

To verify that structures are properly designed

QA Reviews

Secondary strategic goal

To verify that drawings are complete,

coordinated and correct

View drawings through the eyes of a:

• Contractor

• Detailer

• Inspector

• Engineer performing peer review

• Building official

• Young engineer reviewing shop drawings

• Lawyer

• Look at the big picture

• Verify load paths

• Check framing sizes

• Validation of the analysis model

• Review constructability

• Check special connections

• Look for mistakes

• Look for the subtleties

• Look at the drawings through contractor’s eyes.

• Review for clarity/consistency

• Look for omissions

• Look for “little” little things

• Look for “big” little things

• Coordination w/ other consultants

QA Reviews

QA review tactics

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Engineers immersed in projects can miss obvious mistakes.

• Load paths

• Connections

• Inefficient framing

• Wrong loads used

• Missing loads (snow drift, folding partitions, etc.)

• Problems with model

• Wrong “R” factor

• Missing or improper expansion joint layout

• Global stability subtleties

• Local stability and bracing subtleties

• What did the computer analysis miss?

QA Reviews

Look at the big picture

• Any unrealistic load paths?

• Loads jumping in/out of shear walls / braced frames?

• Beware of the infinitely rigid diaphragm?

• Any loads on the structure not in the computer model?

QA Reviews

Verify load paths

Example: Forces

must resolve at

ends of sloping

columns.

QA Reviews

Example: Unrealistic distribution of lateral

loads between lateral load resisting elements.

QA Reviews

Example: Questionable

braced frame forces (due

to infinitely rigid

diaphragm in computer

model).

QA Reviews

Example: Floor diaphragm not strong or stiff

enough to brace the columns.

QA Reviews

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Example: floor diaphragm cut off from braced

frame

QA Reviews

Example: computer software ignoring drag

strut force.

QA Reviews

Example: floor

diaphragm must be

manually designed.

QA Reviews

Check:

• Typical framing to verify the analysis model• Major load carrying members• Wind and seismic loads• Unique framing not in computer model

QA Reviews

Check framing (gravity & lateral)

• Makes QA review easier

• Load paths are easier to follow

• Mistakes are easier to find (computer mistakes)

• Forces designer to think about the connections

• Reduces cost because fabricator details connection for actual required strength – not an arbitrary & usually overly conservative strength.

QA Reviews

Always show reactions on framing plans

Here’s why,Elevators

Escalators

Facades

Davits

Stairs

Monumental stairs

Hangers

Theater rigging

Trusses

Transfer girders

Folding partitions

Special hang points

Rooftop MEP loads

Heavy hung piping

Special loads on joists

Horizontal loads from

rigging

Catwalks

Expansion joints

Unusual framing

QA Reviews

Things requiring special attention

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QA Reviews

Validation of the analysis model

Steel buildings:

Will the pieces fit together?

Can connections be economically designed

and detailed?

Concrete buildings:

Is formwork economical and repetitive?

Can reinforcing steel be easily installed?

(Just because an FEM analysis says it

works, does not mean it can be built.)

QA Reviews

Review constructability

• Critical connections

• Unusual connections

• Connections w/ complex geometry

• Connections w/ large reactions

• Look for problems due to design changes

QA Reviews

Check connectionsExample: Seemingly small changes in slab edge location

during design drastically affect punching shear capacity in

flat plate floor slab

QA Reviews

Example: Slab opening added near column; girder shifted

to avoid opening; girder now connecting to beam but beam

and beam reaction not revised.

QA Reviews

• Wrong reactions

• Members too small

• Improper framing configurations

• Insufficient or missing reinforcing steel

• Punching shear problems

• Missing structural integrity reinforcing steel

• Missing sections and details

• Mistakes in sections and details

• Mistakes in computer model

• Invalid assumptions made in computer model

• Insufficient diaphragm strength / missing

diaphragm connections

QA Reviews

Look for mistakes

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Example: Carelessness can result in objects obscuring

important text. Errors like these can cause structural

failures.

QA Reviews

Example: Spandrels at openings are unbraced and take

lateral wind loads. Design accordingly. Facade braces and

kickers can’t be used to brace facade at stair openings.

QA Reviews

• Column splices at inappropriate locations (mid7

height of 80’ unbraced height).

• Framing through steps in floor slabs

• Floors diaphragms w/ insufficient strength/stiffness

to brace columns

• Incorrect assumptions made in computer model

• Things not checked in the computer analysis

• The “infinitely rigid” diaphragm

• Global stability (“islands of instability”)

• Load path subtleties

• Circular framing

QA Reviews

Look for the subtleties

Example: special column

splices required in tall

unbraced columns

QA Reviews

Example: floor diaphragms need sufficient strength &

stiffness to brace columns

QA Reviews

• Envision you are building the structure and it is the first

time you’ve seen the drawings

• Is everything shown that will allow contractor to build

structure without having to guess or issue RFI’s?

• Is every foot of the building perimeter covered by a

section?

• Is everything clearly indicated?

• Are there any lines on the plans that make no sense?

• Any missing lines?

• Is there any conflicting information?

• Can the drawings be interpreted by someone who is not

an engineer?

• Search the drawings for potential change orders

QA Reviews

Look at the drawings through the eyes of a contractor

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• Look for conflicts between framing plans and

sections/details.

• Inconsistencies with framing

Group similar beams

Consistency = simplicity = economy

• Drafting inconsistencies

• Are sections and details cut in a uniform manner?

QA Reviews

Review for clarity & consistency

• Missing things are the hardest to find

• Missing,

Reactions

Section / details

Dimensions and elevations

Sizes

Reinforcing steel

QA Reviews

Look for omissions

Spelling mistakes are embarrassing 7 especially

words like “momint”, “sheer” and “engeneer”.

QA Reviews

Look for the “little” little things

“Small” drafting errors can cause structural failures.

QA Reviews

Look for the BIG little things

• Dimensions & slab edges

• Facade sections, details and support requirements

• Column locations

• Slab openings (next slide)

• Headroom clearances

• Slab elevations, slopes, depressions and steps

• Floor plans (verify design loads)

• Stairs, elevators, escalators

• Rooftop screen walls, MEP penthouse, parapets*.

QA Reviews

Coordination w/ architectural drawings

Example: Slab opening

cutting off load path to

edge column; opening

not shown on structural

drawings.

QA Reviews

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MEP coordination

• Heavy piping & equipment loads

• Large ducts (headroom interference with framing)

• Beam web penetrations

• Slab embedded electrical conduit

• Below grade utilities

QA Reviews

Coordination with other consultants (MEP) Example: Duct and pipe penetrations through beams

QA Reviews

Example: slab7embedded electrical conduit.

QA Reviews

• Understanding software limitations

• Manually verifying computer analysis

• Architectural and MEP changes after structural

design is completed.

• Changes during construction that slip through

the cracks of the QA process.

• Climbing the BIM learning curve

• Improving communication skills

QA Reviews

Ongoing challenges

The six parts of a QA program,

• Project Deliver System

• Design standards

• Drawing & modeling standards

• Knowledge base

• Training for engineers

• Multiple and ongoing QA reviews during design

QA reviews serve two purposes,

• Redundancy

• Monitor effectiveness of QA program.

QA is a continual process (ongoing QA)

Quality Assurance is everyone’s responsibility

Success requires teamwork and communication!

SummaryThank you!Questions?

Clifford Schwinger, P.E.cschwinger@harmangroup.com

Phone: 610.337.3360

www.HarmanGroup.com