Benchmarking of Nonlinear Geotechnical Ground Response Analysis Procedures - 2G03

Project Title—ID Number	Benchmarking of Nonlinear Geotechnical Ground Response Analysis Procedures - 2G03
Start/End Dates	10/1/05 – 12/31/06
Funding Source	PEER-Caltrans
Project Leader (boldface) and Other Team Members	Jonathan Stewart (UCLA/F), Onlei Annie Kwok (UCLA/GS), Walter Silva (Pacific Engineering/I), Robert Kayen (USGS/O)

Project goals and objectives

1. Obtain Vs profiles for vertical array sites in Japan using SASW testing.
2. Process Italian strong motion data (about 500 records).
3. Completion of validation exercise from PEER Lifelines Project 2G02 and preparation of final report.

Role of this project in supporting PEER's mission (vision)

This project is developing site and ground motion data needed for ongoing ground motion research projects.

The final stage of 2G02 project work involves the validation of nonlinear ground response analysis codes, which contributes to the estimation of IM.

Methodology employed

Shear wave velocities are being measured using SASW techniques. The field work is now complete and data analysis is in progress.

The data processing follows normal protocols for the PEER-NGA project. This work is complete.

The validation work at the end of 2G02 comprises analysis of vertical array data.

Brief Description of previous year's achievements, with emphasis on accomplishments during last year (Year 8)

Previous years accomplishments were in the 2G02 project.

We have completed a significant theoretical verification exercise in which consensus guidelines were developed regarding specification of input motions for nonlinear codes and specification of viscous damping. These results are being synthesized into a journal paper that will be submitted for review shortly.

We have completed a set of blind predictions for the Turkey Flat site (2004 Parkfield earthquake) and have compared our results to those of our developer teams. This work is being published in conference proceedings.

We have completed exercises that have demonstrated significant differences in the codes when they are used with large input motions. This is being further investigated in ongoing work. Describe any instances where you are aware that your results have been used in industry Our guidelines on code usage are being implemented in industry by users of the codes exercised in this project (DEEPSOIL, DMOD, TESS, OPENSEES, SUMDES).

Expected milestones & deliverables

• - Completion of Vs logs for Japanese downhole array sites.
• - Completion of Italian data processing
• - Completion of downhole array studies
• - Development of recommendations for parameter selection related to backbone curves and parameters that control the shape of hysteresis curves.
• - Completion of final project report.