SSI Workshop 2015

SCEC Workshop on Soil-Structure Interaction of Complex Systems

Organizers: Jacobo Bielak (CMU), C.B. Crouse (AECOM), Tom Jordan (SCEC/USC)

Date: Thursday, January 29, 2015 (08:00-15:30)

Location: USC Campus Center: Steven and Kathryn Sample Hall (Trojan Ballroom C/D), Los Angeles, CA

Participants: 30 (by invitation only)

Overview

The Southern California Earthquake Center (SCEC) will host a one-day workshop on soil-structure interaction (SSI) simulation of complex building and non-building systems during strong earthquakes. The workshop will take place on January 29, 2015 in Los Angeles at the University of Southern California.

The evaluation of SSI effects during earthquakes is currently conducted, by and large, using variations of methods based on highly simplifying assumptions that were developed originally over fifty years ago. For instance, the current SSI provisions in the ASCE 7-10 standard are based on simplified analytical methods developed in the 1970s. Minor improvements have been made since then and revisions to the SSI provisions in the ASCE 7 standard are being proposed in the current code cycle. This revision, however, is still based on the same simplified equivalent linear model on which the original recommendations were based.

Structural engineers typically use commercial software for dynamic analyses that can model the 3-D geometry and stress-strain characteristics of the structure in great detail, but these software programs model the SSI effects crudely, if at all. Similarly, geotechnical engineers use commercial software that can model the complex constitutive behavior of the soil, but these software programs cannot accommodate complex 3-D structural models. Another potentially important factor is the spatial variability of ground motion and how to model it in complex geologic media; this problem is especially important for elongated structures such as dams and bridges, and for other complex multistructural systems such as nuclear power plants. With the increased attention being paid to the nation’s infrastructure, it is now an appropriate time to bring together seismologists and engineers (a) to assess current practice in SSI and related recent methodologies, and (b) to examine unmet needs and potential methodologies for addressing such needs.

Agenda

Presentation slides may be downloaded by clicking each title. PLEASE NOTE: Slides are the author's property. They may contain unpublished or preliminary information and should only be used while viewing the talk.

08:00 - 08:30	Welcome Breakfast
08:30 - 08:45	Introductory remarks and meeting agenda	Jacobo Bielak
09:00 - 10:30	Current state-of-practice and needs for SSI effects in (Greg Deierlein, moderator; George Mylonakis, reporter)
	* Foundation-soil interactions	Jonathan Stewart
	* Building structures	Robert Pekelnicky
	* Buildings and infrastructure systems	Ibrahim Almufti
	* Nuclear power container structures	Enrique Luco
	* Dams: "SSI Analysis with Soil Modeled as a Continuum"	Ethan Dawson
10:30 - 11:00	Discussion
11:00 - 11:45	Methods of analysis and related software (Domniki Asimaki, moderator; Ethan Dawson, reporter)
	* SASSI	Farhang Ostadang
	* LLNL software	Jerome Solberg
	* Nonlinear analysis	Justin Coleman
11:45 - 12:00	SCEC activities related to engineering applications	Tom Jordan
12:00 - 13:00	Lunch
13:00 - 15:30	Discussion of needs and desirable actions and developments (C.B. Crouse, moderator; Sanaz Rezaeian, reporter)
15:30	Adjourn

Participants

Norm Abrahamson (PG&E) Ibrahim Almufti (Arup) Domniki Asimaki (Caltech) Mohsen Beikae (MWD of SoCal) Jacobo Bielak (CMU) Justin Coleman (Idaho National Lab) C.B. Crouse (AECOM) Ethan Dawson (AECOM) Greg Deierlein (Stanford)	Asa Hadjian (DNFSB) John L. Harris (NIST) Ben Husmand (Hushmand Assoc) Tran Huynh (SCEC/USC) Tom Jordan (SCEC/USC) Dennis LaChaine (MWD of SoCal) Enrique Luco (UCSD) Nico Luco (USGS) Phil Maechling (SCEC/USC)	Mike Mehrain (AECOM) George Mylonakis (Univ of Patras) Farzad Naeim (Farzad Naeim, Inc.) Farhang Ostadan (Bechtel) Bob Pekelnicky (Degenkolb Engineers) Sanaz Rezaeian (USGS) Wolfgang Roth (AECOM) Jerome M. Solberg (LLNL) Jonathan P. Stewart (UCLA)