2372003 - Workshop on Simulation and Seismic Performance of Deep Foundations

Project Title/ID Number	Workshop on Simulation and Seismic Performance of Deep Foundations—2372003
Start/End Dates	10/1/03—9/30/04
Project Leader	Ross Boulanger (UCD/F)
Team Members

F=faculty; GS=graduate student; US=undergraduate student; PD=post-doc; I=industrial collaborator; O=other

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1. Project Goals/Objectives:

The proposed workshop will be the culmination of a comparative evaluation of emerging design methods for pile foundations in liquefied ground. The overall goals are as follows:

Provide a comparative evaluation of competing design recommendations against experimental and case history data.
Hold a workshop to explore the results of the preceding comparative evaluation, identify areas of consensus, and identify areas of major debate.
Publish a Workshop Proceedings that summarizes the consensus design guidelines and/or competing proposals for design guidelines, along with the comparative evaluations and findings from the workshop.

The Workshop Proceedings will be an extremely valuable asset for engineering practice, regardless of whether complete consensus is obtained. The details of the proposed research effort and workshop organization are described below.

2. Role of this project in supporting PEER’s mission (vision):

This workshop supports PEER's efforts toward developing performance based design methodologies for bridge and building systems by addressing a problem that is of strong interest to owners and a major source of uncertainty in current design and assessment practices.

3. Methodology Employed:

The coordinated plan of these efforts is proceeding as follows:

A small group, consisting of I. M. Idriss, Tom Shantz (Caltrans), and R. W. Boulanger, was formed to refine the workshop plan. In addition, the workshop has been coordinated with Professor Kohji Tokimatsu at Tokyo Institute of Technology's Urban Earthquake Engineering Center, which will support the participation of Japanese experts.
The workshop date has been set as March 16-18, 2005. Key participants have been invited and are willing to perform comparative evaluations of their design/analysis methodologies against a common set of physical test data and case histories.
A schedule for the comparative evaluations, paper submissions, and workshop organization has been set.
A summary paper on workshop discussions and comparisons will be prepared.

4. Brief Description of past year’s accomplishments (Year 6) & more detail on expected Year 7 accomplishments:

In addition to planning of the workshop, some initial comparisons of design methodologies have been performed. The figure below shows results of one such comparison. This figure compares results of a limit equilibrium approach by Dobry et al. (2003) and a Beam on Nonlinear Winkler Foundation approach by Brandenberg (supported under project 2312003). The comparisons are for two different pile foundations having very different lateral stiffness', and show that these two different approaches are capable of producing very comparable results for the deflections and bending moments induced by lateral spreading of a non-liquefied crust layer over liquefied sand.

5. Other Similar Work Being Conducted Within and Outside PEER and How This Project Differs:

There are no competing plans for such a workshop that I am aware of.

PEER is in a unique position to lead the establishment of engineering guidelines for the design of pile foundations in liquefied and laterally spreading ground, which is widely recognized as a major issue in earthquake engineering practice and hazard mitigation. PEER and PEER researchers have been contributed to the rapid development of our understanding of the mechanisms of soil-pile interaction in liquefied and laterally spreading ground, such as obtained through research projects funded by the PEER-core, PEER-Lifelines, Caltrans, and other organizations.

6. Plans for Year 8 if project is expected to be continued:

The March 2005 date of the workshop was set to avoid conflicts with other US and Japanese events, and is later than original anticipated. This requires extending this project into next year, but with no additional funding.

7. Describe any actual instances where you are aware your results have been used in industry:

8. Expected Milestones & Deliverables:

The major deliverable will be the workshop proceedings. I propose that the Workshop Proceedings be published as an ASCE Special Publication under joint sponsorship of the ASCE-GeoInstitute and PEER. Such an arrangement would assure the widest possible distribution. The chair of the GeoInstitute Publications Committee is receptive to this plan, and I will explore the necessary planning arrangements.