Development of ISO23469 - Seismic Action for Designing … · 2007. 1. 10. · ACECC workshop on Harmonization of Design Codes in the Asian Region Nov. 4, 2006, Taipei, Taiwan Development

ACECC workshop on Harmonization of Design Codes in the Asian Region

Nov. 4, 2006, Taipei, Taiwan

Development of ISO23469 - Seismic Action for Designing Geotechnical Works-, and its follow-up project

Shinichiro MoriEhime University

Note: ACECC stands for Asian Civil Engineering Coordinating Council ACECC workshop on Harmonization of Design Codes in Asian Region, Nov 4, 2006, Taipei Shinichiro Mori

Contents of today’s presentation

ISO23469- Seismic actions on geotechnical worksand related issues

- ISO/TC98- ISO3010 – Seismic action on structures- History of development of ISO23469- Features of ISO23469- Follow-up project of ISO23469- Harmonization of design code in the globe

ISO/TC98 Bases for design of structures

Established in 1961Secretariat : Polish Committee for StandardizationMembers: 22 P-members and 35 observers

(one member or observer from each country)Main tasks SC1: terminology and symbolsSC2: reliability of structuresSC3: loads, forces and other actions on structures

including seismic actions on structures and geotechnical works

buildings and civil engineering works

ISO2394

ACECC workshop on Harmonization of Design Codes in Asian Region, Nov 4, 2006, Taipei Shinichiro Mori

ISO3010 Bases for design of structures -Seismic actions on structures

ScopeThis International Standard specifies principles of

evaluating seismic actions for the seismic design of buildings, towers, chimneys, and similar structures.

Most of the principles are applicable also to dummy structures such as bridges, dams, harbour installations, tunnels, fuel storage tanks, chemical plants, conventional power plants, etc. (in WD in 1997)

Some of the principles can be referred to for the seismic design of structures such as bridges, dams, harbour installations, tunnels, fuel storage tanks, chemical plants, conventional power plants, etc. (changed in 1998)


Necessity of new IS for civil worksSeismic actions on superstructures of bridges and buildings come from same mechanism.

Buried structures, Soil structures, Foundations

Mechanism distinctions from buildings are soil-structure interaction, soil displacement.

Seismic actions on geotechnical worksACECC workshop on Harmonization of Design Codes in Asian Region, Nov 4, 2006, Taipei Shinichiro Mori

ISO23469 Bases for design of structures- Seismic

actions for designing geotechnical worksScope

This International Standard provides guidelines for specifying seismic actions for designing geotechnical works, including buried structures (e.g. buried tunnels, box culverts, pipelines, and underground storage facilities), foundations (e.g. shallow and deep foundations, and underground diaphragm walls), retaining walls (e.g. soil retaining and quay walls), pile-supported wharves and piers, earth structures (e.g. earth and rockfill dams and embankments), gravity dams, landfill and waste sites.


History of development of ISO23469 -Seismic actions for designing geotechnical works

Dec., 1998 Application of ISO3010 on civil works was avoidedMay, 2000 Establishment of International SC in Earthquake

Committee in JSCEMay, 2001 Proposal of NWI from Japan at TC98 meetingFeb., 2002 Establishment of TC98/SC3/WG10 by Prof. Iai as

Convener; after that, 9 WG10-meetings were held3 of the 9 meetings in conjunction with TC98 meetings

Feb., 2005 DIS successfully obtained 100% approval votes, so it was automatically approved as IS.Satisfactory accomplishment within 3 years as per rule.

Nov., 2005 This International Standard was published.As a result, Japanese experiences after Kobe earthquake and US experiences after Northridge were reflected to the principles of this IS as well as European ones.


Establishment of WG for ISO23469 and invitation of related liaisons

Establishment of WG10 with 18 international experts including 8 Europeans, 6 Asians, 3 North Americans and 1 Oceanic

Invitation of some members as liaisons with CEN/TC250/SC8 and ISSMGE/TC4

Organization of the nationwide reviewers group in USA

Continuous and strong support from Japanese domestic WGand responses from academic and experienced practicing people in Japan.


Basic policy of development of ISO23469

To provide guidelines for experienced practicing engineers and code writers

To provide only principles, no specific method

To provide new methodologies that might lead the-state-of-practice to be developed over next decades in a global scale

To basically cover current design codes in the world


Basic stance for development of ISO23469

• To presume well-experienced practitioners as users• To make it work throughout the next decade• To consider balance with ISO3010• To put stress on Soil-Structure Interaction• To cover well-used design methods• Not to exclude newly developed technique• Not to describe the detail of modelling• Not to provide choice of methods and models


Features of WG activity during development

WG activity was transparent and open.- WG10 Website installation- All minutes of meetings and all WD on the Web- Some meetings extended to any participants of academic conferences held in conjunction with WG meetings

Participation through correspondence also worked well.- Constructive comments from members and reviewers and consideration on them into revise of draft at all steps


Contents of ISO23469

1 Scope2 Normative references3 Terms and definitions4 Symbols and abbreviated terms5 Principles and procedure6 Evaluation of earthquake ground motions,

ground failure, and fault displacements7 Procedure for specifying seismic actions8 Seismic actions for equivalent static analysis9 Seismic actions for dynamic analysis


Collapse of highway embankment during Niigata-ken Chuetsu earthquake in 2004


Just after the event After repair14 months was needed all the damage were completely repaired.

Heavy deformational damage to tunnel during 2004 Niigata-ken Chuetsu earthquake

Kizawa road tunnel Estimated mechanism

Tunnel

Displacement u1

u2


Inclination10 deg.

Horizontal displacement

20cm

Diameter 40cm

Damage to pile due to Damage to pile due to horizontal displacement in horizontal displacement in liquefied ground during liquefied ground during 1993 Hokkaido 1993 Hokkaido NanseiNansei--okiokiearthquakeearthquake

Keywords

Pile foundationLiquefactionDisplacementSoil-structure interaction


Damage to a gravity dam due to fault displacement with 7.5m Damage to a gravity dam due to fault displacement with 7.5m of relative displacement during 1999 Chiof relative displacement during 1999 Chi--chi earthquakechi earthquake

7.5 m


Primary issues for specifying seismic actions

Seismic actions for designing geotechnical works

Evaluation of earthquake ground motions, ground failure, and fault displacementsSeismic hazard analysisSite response analysis and assessment of liquefac tion potentialSpatial variationFault displacements, ground fai lure, and other geotechnical hazardsParaseismic influences

Specifying seismic ac tions

Equivalent static analysis

Simplified equivalent static analysis

Detai led equivalent static analysis

Seismic actions from a superstructureSeismic actions without spatial variationSeismic actions with spatial variationSeismic earth and hydro-dynamic pressuresSeismic actions on soil and structure massesEffects of soil liquefaction and induced ground displacementEffects of fault displacements

Seismic actions for a seismic coefficient approachEffects of soil liquefaction and induced ground displacement

Dynamic analysis

Simplified dynamic analysis

Detai led dynamic analysis

Seismic actions from a superstructureSeismic actions without spatial variationSeismic actions with spatial variationSeismic actions on soil and structure massesEffects of soil liquefac tion and induced ground displacement

Seismic actions for a soil-structure systemEffects of soil liquefaction and induced ground displacement

Clause 5Clause 6

Clause 7

Clause 8

Clause 9

Annex A of ISO23469


Informative Annexes： 1-7 of 14Annex A Primary issues for specifying seismic actionsAnnex B Upper crustal rock, firm ground, and local soil

depositAnnex C Design situations for combination of actionsAnnex D Seismic hazard analysis and earthquake ground

motionsAnnex E Site response analysisAnnex F Spatial variation of earthquake ground motionAnnex G Assessment of liquefaction


Informative Annexes： 8-14 of 14Annex H Seismic actions defined for various models of

geotechnical worksAnnex I Soil-structure interaction for designing deep

foundations: phase for inertial and kinematicinteractions

Annex J Limitations in the conventional method and emerging trend for evaluating active earth pressure

Annex K Effects of liquefaction considered in various models of geotechnical works

Annex L Evaluation of other induced effectsAnnex M Concepts of response control and protectionAnnex N Interdependence of geotechnical and structure

designs


Features of ISO23469

- Introduction of site specific design- Design philosophy for extreme event- Modeling of soil-structure interaction- Consideration of spatial variation of seismic

motion- Recommendation of coupled analysis for SSI- Stimulating discussions including option


Two stage determination of seismic actions on geotechnical works

Stage 1- Evaluation of basic variables for seismic action- Reference ground motion, associated phenomena

Stage 2- Determination of seismic action based on basic variables- Important role of SSI


Flowchart for specifying seismic actions Stage 1 (Clause 6) Stage 2 (Clause 7)

Select type of analysis

Select model and method of analysis

Perform geotechnical characterisation

Specify performance criteria

Reference earthquake motions

Evaluate seismic actions

Probabilistic or deterministicapproaches

Two-stage determination is adopted.ACECC workshop on Harmonization of Design Codes in Asian Region, Nov 4, 2006, Taipei Shinichiro Mori

http://www.bousai.go.jp/chubou/9/zuhyou_2-2.pdfACECC workshop on Harmonization of Design Codes in Asian Region, Nov 4, 2006, Taipei Shinichiro Mori

Simulated seismic intensity map when historically largest earthquake in Japan is

supposed to occurDeterministic approach is adequate for evaluating extremely low probability event.

Methods for site response analysis

a) Empirical b) Site-specific c) Site-specific simplified d) Site-specific detailedanalysis simplified analysis dynamic analysis dynamic analysis


Stimulating discussions“As an option, the owners or authorities in charge of the

geotechnical works may decide at their own risk to perform no explicit seismic design, or to perform the minimum design required by applicable codes, if the consequence of a failure is very low”.

This statement was proposed by Japan for developing countries from the viewpoints of vulnerability and reparability. It had been controversial. It was eventually deleted.

Should this statement have been involved or not?


Earthquake motions

Sea

Seabed

Firm ground

Caisson

Hydro-dynamicpressure

Inertiaforce

Earthpressure

Firm ground

CaissonSea

Seabed

Classification of types of analyses based on model of soil-structure interaction

a) Simplified model b) Detailed modelModel of analysis for caisson quay walls for example

Simplified: Seismic action modeled on local systemDetailed: Seismic action evaluated in global system


Classification of analysis

Equivalent staticClause 8

DynamicClause 9

SimplifiedSimplified

equivalent static8.1

Simplifieddynamic

9.1

DetailedDetailed

equivalent static8.2

Detailed dynamic9.2

Based on combination of type of analysis and modeling of SSI


Different models of analysis(Retaining walls)

LateralDisplacement3.5 m

Inclination4.1゜

+4.0 m

-36.0 m

Vertical Displacement 1.5 m

Hydro-dynamic pressureHorizontal component of inertia force

Seismic earth pressure

Gravity + Vertical component of inertia forcea

a see H.1

Simplified equivalent static Detailed dynamic (Seismic coefficient method) (FEM using effective stress approach)


Seismic actions with spatial variation

• Seismic actions for simplified equivalent static (1A) and detailed dynamic analyses (2A)

Firm groundLumped mass-equivalent spring systemidealises the local soil deposit

Equivalent springs

Lumped mass

Ground surface

Tunnel - or tube-likeunderground structure

Tunnel- or tube-like underground structure

Tunnel- or tube-like underground structure

Transverse seismic ground displacement

Longitudinal seismic ground displacement

Subgrade reaction springa

aThe subgrade reaction springs maybe assumed rigid for undergroundstructure with a small cross sectionsuch as pipelines.

Interface shear spring

(a) Transverse actions

(b) Longitudinal actions

a) Simplified e.s. model b) Detailed dyn. modelAnnex H, H.5 Tube-like underground structures


History of follow-up projectDevelopment of ISO 23469 was finalized in Paris meeting

in February 2005.

Development of Technical Report on design examples was suggested as a follow-up project in Paris meeting.

The proposal of the Preliminary Work Item developing the TR was submitted and approved in Ottawa meeting in October 2005.

WG10 has been discussing scope and contents of New Work Item aimed at being proposed at Berlin meeting in November 2006.


Scope of NWI

Providing design examples for use of ISO23469

Publishing design examples of geotechnical works based on ISO23469 in the form of a Technical Report (TR)

ISO23469 provides only principles, so it is difficult to design by only using this standard. Design examples can demonstrate how to use it.


Tank and foundation Detailed dynamic model

Design example of pile foundation of PC tank for LNG (1)


Design example of pile foundation of PC tank for LNG (2)

- 2D-FEM- Axial symmetric FEM- 3D-FEM


Policy of collection of design examples- Demonstrating how to use this ISO for practicing engineers and

code writers by showing design examples based on ISO23469- Based on documents published or to be published- Having important things need to be covered- Focusing evaluation of reference earthquake ground motion

should be documented in detailed as a common issue- Having combination of simplified and detailed analyses- Description should be cared in terms of conformity with

requirement and recommendation in ISO23469.- Having stress on methodologies recommended by WG- Describing not only seismic actions, but also performance criteria

and design of superstructure


Overall check on conformity

Convenient for comparison among examples

ISO23469

Type of analysis Reason*


Fault displacements and other geotecnical hazards 6.5Paraseismic influences 6.6


*Reason for choosing the type of analysis

Check sheet of design example in terms of conformity with ISO23469

6.3

6.4

789

5.1.2

5.1.36.16.2

5.1.4

Overall conformity with ISO23469

Seismic actions on geotechnical worksPerformance criteria parametersOutline of analysis

Outline of evaluationOutline of evaluation

Items

OthersServiceabilitySafetyOthers

Site response analysis and assessment of liquefactionpotential

Spatial variation of earthquake ground motions

Outline of analysis

Outline of analysis

Performance objectives

Reference earthquake motions

Perfomance criteria

Design working life

ServiceabilitySafetyOthersServiceabilitySafety


Harmonization of design code in the globe

What is important is to have common terminology, to exchange information, to share our problems.

Harmonization in the world should be achieved, so Asian regions having diverse countries should be involved more actively.

Thank you.


Documents

Development of ISO23469 - Seismic Action for Designing … · 2007. 1. 10. · ACECC workshop on Harmonization of Design Codes in the Asian Region Nov. 4, 2006, Taipei, Taiwan Development