The overall project goal is to utilize the full-scale data assess current methods for estimating the effect of lateral spreading on pile foundations and pipelines, and develop new procedures if necessary. Specifically for Year 6, our objectives are to:

• Back calculate P-y curves for all specimens for both tests
• Model Experiment 1 using OPENSEES.

The PEER Lifelines Program funded the project with $610,000 in the initial year, for both experiments in Japan. This was matched by over $2.5 million by the Japanese to make the total effort over $3 million. We are proposing that PEER Core fund the analysis portion of the project. For this effort in Year 6, we request funding on the order of $65,000. This will fully fund a new MS student, and partially fund the PI’s (1/2-month for Professors Ashford and Uang), as well as partially fund a post-doctoral researcher that actually carried out the experiment in Japan (50%-time Teerawut Juirnarongrit). It is understood that PEER researchers at other Universities will be able to collaborate with us on the analyses within their existing funds, otherwise additional funding would be required.

Two tasks are proposed for Year 6:

1. Back-calculate P-Y curves during lateral spreading for both tests based on the moment data already completed. This task will include interpretation of the forces induced on the pipelines, piles, and pile caps during the lateral spreading.
2. Use OPENSEES to model the entire result of the two tests (including GPS, strain, and pore pressure data) in an effort to assess the capabilities of the PEER numerical platform. If this is successful, it will be proposed in Year 7 to extend the results of the experiment using OPENSEES to larger lateral deformations. Collaboration with other PEER researchers will be essential.

In Year 5, two full-scale experiments using controlled blasting were conducted in November and December 2001 in the Port of Tokachi on Hokkaido Island, Japan, to study the performance of lifeline facilities subjected to lateral spreading. This research project was the joint collaboration between the University of California, San Diego, (UCSD) and several Japanese organizations led by the Port and Airport Research Institute (PARI). The primary objective of the test was to assess the performance of lifelines subjected to lateral spreading using controlled blasting. The PEER Lifelines Program funded UC San Diego’s participation in the test with support from Caltrans, Pacific Gas & Electric and the California Energy Commission.

In all, UCSD installed 6 test specimens. The pile specimens in the experiment program consisted of a single pile, a 4-pile group, and a 9-pile group. In addition, two natural gas pipelines and one electrical conduit were installed. All of them were extensively instrumented with strain gauges to measure the distribution of moment in the specimens during lateral spreading. Other instrumentation, including pore pressure transducers, GPS units, and slope inclinometers, were also installed to measure the degree of liquefaction as well as the movements of soil and lifelines. This data will allow us to compute the loading conditions during lateral spreading, as well as to assess the capabilities of our numerical models being developed within PEER. The objectives of this study is to conduct damage and performance assessments of those lifelines subjected to lateral spreading, as well as to evaluate loading conditions on the structures during lateral spreading. Currently, the final draft test report on the experimental portion of the work has been completed and submitted to PEER Lifelines Program, which completed the current scope.

The PI has conducted and is currently conducting research sponsored by Caltrans on the full-scale behavior of deep foundations in liquefied sand. These experiments also utilize controlled blasting to induce liquefaction. Though primarily focused on Cast-In-Drilled-Hole (CIDH) piles, these experiments also considered pile groups. This proposed research differs from these projects in two primary ways. First, in the previous research, only the soil in the immediate vicinity of the pile was liquefied and inertial loading was simulated used hydraulic actuators. In the Japan test, the soil was liquefied for a great distance around the piles, and loading was be from lateral spreading soil. Secondly, the piles in the previous experiments had the free-head condition. In the proposed research, a pile cap was incorporated to test the fixed-head condition. The PI’s are not aware of any ongoing full-scale field experimentation on the performance of pipelines subjected to lateral spreading.

• January 2003: Data from Japan Experiments made available to PEER Core researchers.
• June 2003: P-y Curves back calculated for all specimens for both experiments.
• September 2003: Preliminary OPENSEES analyses on Experiment 1.

• PEER Quarterly Reports
• Data CD from both experiments
• Final Report on back calculated P-y curve