Structural Precast Concrete Structures in Seismic Areas

USA experience

INTERNATIONAL SEMINAR ON PRECAST

CONCRETE STRUCTURES

- Precast Structures in the World -

21 October 2010

Structural Precast Concrete Structural Precast Concrete

Structures in Seismic Areas Structures in Seismic Areas

USA experienceUSA experience

INTERNATIONAL SEMINAR ON PRECAST INTERNATIONAL SEMINAR ON PRECAST

CONCRETE STRUCTURESCONCRETE STRUCTURES

-- Precast Structures in the World Precast Structures in the World --

21 October 201021 October 2010Jason Krohn, P.E.

Managing Director, Technical Activities

Precast/Prestressed Concrete Institute

Chicago, IL, USA

PCI - Technical InstitutePCI - Technical Institute

1. Industry Standing

2. Clearly Stated Purpose

3. Broad Professional Involvement

4. Governance and Consensus

5. Research

6. Validation

7. Dissemination

8. Certification of Personnel

9. Certification of Fabrication Process

10.Independent Audits

11.Feedback and Recourse

12.Continuing Commitment

Characteristics of Technical Institutes

PCI’s Continuing CommitmentPCI’s Continuing Commitment

• PCI founded in 1954

• PCI certification established in 1967

• Over 50 on-going technical committees

• Full staff of technical, marketing, and administrative support

• Annual allocated budget

PCI MembershipPCI Membership

• 263 Producer Members

• 88 Supplier Associate Members

• 128 Erector Associate Members

• 2,123 Individual Members– 1,120 Professionals

– 135 Associate Professionals

– 149 Affiliates

– 634 Students

– 85 Life Members

• PCI Journal

• Ascent

• Aspire

• PCI Design Handbook, 7th Edition

• PCI Bridge Design Manual

PCI’s PublicationsPCI’s Publications

US Diaphragm PracticeUS Diaphragm Practice

• Double Tees (Topped or Untopped)

US Diaphragm PracticeUS Diaphragm Practice

• Hollowcore

Observed Diaphragm Challenges Observed Diaphragm Challenges

• 1994 Northridge Earthquake (6.7 Mw)

• 2010 Mexicali, Mexico (7.2 Mw)

Technical Institute CharacteristicTechnical Institute Characteristic

5. Research

• Address problems

• Drive continuous improvement

• Support/fund practical research

• Publish internal research results

• Disseminate external research results

Development of a Seismic Design Development of a Seismic Design

Methodology for Precast DiaphragmsMethodology for Precast Diaphragms

Robert Fleischman, Dichuan Zhang, and Ge Wan

University of Arizona

Clay Naito, Richard Sause, Liling Cao, Rui Ren, and Wesley Peter

Lehigh University

Jose Restrepo, Matt Schoettler, Andrea Belleri, and Carlos Blandon

University of California at San Diego

Jorge Rivera

The Rose School

S.K. Ghosh

S.K. Ghosh Associates, Inc.

Diaphragm Seismic Design Methodology (DSDM) Project

PCI Research & Development PCI Research & Development

Producer Members

University of CaliforniaSan Diego

Jose’ Restrepo, PI

Producer Members

Lehigh UniversityClay Naito, PI

Richard Sause, Co-PI

Industry Advisory Panel

Industry LiaisonS. K. Ghosh, Co-PI

University of ArizonaRobert FleischmanConsortium Leader

DSDM Task Group

DSDM ConsortiumDSDM Consortium

� the forces, displacements and deformations for which the

diaphragm should be designed

� the existing diaphragm connection details that can

provide this performance

� the required stiffness of the diaphragm relative to the

lateral force resisting system (LFRS).

�Develop an industry endorsed seismic design

methodology for precast concrete diaphragms including:

� Charles Pankow Foundation (CPF) deliverable is the development,

demonstration and codification of a precast concrete diaphragm

system for high seismic zones

DSDM Research ObjectivesDSDM Research Objectives

Half-Scale Shake Table TestHalf-Scale Shake Table Test

7.0 m

4.9 m16

.5 m

DSDM Shake Table Test FactsDSDM Shake Table Test Facts

• Shake Table Facts

– 4+ year long research project

– 3.5 = Floor aspect ratio

– 16 significant input ground motions

– 640 sensors to capture response

– 14 cameras to help with visualization

1.080.61MCEBerkeley, CAHigh

Note: DBE = design-basis earthquake; MCE = maximum considered earthquake;

g = acceleration due to gravity; PGA = peak ground acceleration

0.720.41DBEBerkeley, CAHigh

1.140.59DBESeattle, WAModerate

1.490.30DBEKnoxville, TNLow

Scale factorScaled PGA, gTarget levelSiteSeismicity

Structure Level (University of California San Diego)

Diaphragm Level (University of Arizona)

Detail Level (Lehigh University)

�Diaphragm seismic force

�Diaphragm flexibility limit

�Overstrength among diaphragm reinf.

�Diaphragm strength and stiffness

FpxFpxFpx

FE Pushover Analysis 3D FE Dynamic Analysis

MDOF Dynamic Analysis Scaled Shake Table Test

√√√√

�Strength and ductility characteristics of typical diaphragm details

�Connection classification

Full-Scale Detail Tests Hybrid Testing of Joints

Design DeliverablesDesign Deliverables

Appropriate Diaphragm

Design Force, ΩFpx

Structure Level Diaphragm Level Detail Level

Appropriate Capacity wrt

Reinforcement GroupsAppropriate Detailing of

Reinforcing Elements

Design PhilosophyDesign Philosophy

DSDM Project FundingDSDM Project Funding

• US $2.5 million research program

– National Science Foundation

– George E. Brown Jr. Network for Earthquake Engineering Simulation

– Charles Pankow Foundation

– Precast/Prestressed Concrete Institute

– Precast, prestressed concrete industry

� Concrete Tech� Knife River� Central Premix� Gibbons Erectors� Nelson Stud

� Splice Sleeve

Design Procedures and CodificationDesign Procedures and Codification

• 2009 NEHRP Provisions, Part 3– Now published

• ICC-Evaluation Report– ~18 month timeframe

• ACI-ASCE 550 standard document– Reference within ACI 318-14 and IBC 2015

• PCI Journal articles

PCI Journal ArticlesPCI Journal Articles

• For more information:

Winter 2009

Sept-Oct 2005

Nov-Dec 2005

PCI Website: www.pci.orgPCI Website: www.pci.org

Thank you!Thank you!

For more information contact:

Jason Krohn, PE

1-312-786-0300

jkrohn@pci.org

www.pci.org