Lotung large-scale seismic experiment and soil-structure interaction method validation

Abstract This paper describes the Electric Power Research Institute's (EPRI) current on-site large-scale soil-structure interaction (SSI) research. The objectives of the research are: (1) to obtain an earthquake database which can be used to substantiate SSI models and analysis methods; (2) to develop realistic SSI analysis guidelines and procedures based on experimental-analytical correlation; and (3) to quantify nuclear power plant reactor containment and internal component's seismic margin based on earthquake experience data. To meet the objectives, two model structures were sited in a high seismic region, Lotung, Taiwan, under the joint sponsorship of EPRI and the Taiwan Power Company (Taipower). The model structures which simulate scaled-down nuclear containments ( 1 4 - and 1 12 - scale ) were constructed and instrumented within an existing strong motion array (SMART-1) deployed by U.C. Berkeley under a U.S. National Science Foundation grant. The instrumentation layout associated with the model structures included accelerometers on the models, on the internal components, on the ground surface, and in the ground. These instrumentations are to provide information required for validation and qualification of SSI models. Between September 1985 and November 1986, 18 earthquakes ranging from Richter magnitude 4.5 to 7.0 were recorded. The analysis phase of the research was conducted with the cooperation of the U.S. Nuclear Regulatory Commission (NRC) and Taipower. A round-robin approach was utilized with emphasis on blind predictions and independent assessment of existing methodologies. A total of 13 research teams from the United States, the Republic of China, Japan, and Switzerland participated in the effort. A workshop was held in December 1987 where research results and findings were presented. Further effort is ongoing to synthesize the results and findings for providing technical bases of developing improved SSI analyses guidelines and procedures.