Study on the calculation of the displacement of Reinforced soil retaining wall due to seismic wave on Energy-Based method

抄録

The reinforced soil retaining wall has been widely constructed since 1990’s because of the highly seismic performance, which was recognized in survey on earthquake disaster of Hyogoken-Nanbu Earthquake. However, the damages of such structure were reported in survey on earthquake disaster of Great East Japan. According to the detail investigation, although the appropriate drainage facilities had been designed and constructed, the reinforced structures which suffered from earthquake had high ground water level. The past study of test results, a series of dynamic centrifuge model tests on the multi-anchor reinforced soil wall (MAW) due to seepage flow showed that the reinforced area which constructed between facing panel and anchor plate behaved as one body under 2 m/s2 of earthquake acceleration. In this paper, the behaviors of reinforcement soil structure of multi-anchor during earthquake are discussed. The dynamic centrifuge model tests on multi-anchor wall were also conducted to clarify the deformation mode of reinforced area. In this test series, the grease was applied to neglect the friction between model ground and model container, and the acrylic plate was placed on the Teflon plate whose coefficient friction was investigated. To verify whether the displacement of reinforced area can be calculated or not, the Energy-Based Method for sliding during seismic wave was adopted. The calculated values of displacement of reinforced area which constructed with smaller relative density than usual construction, were smaller than those of centrifuge model tests. However, the displacement of the model case with high relative density was close to the calculated value. It shows that the deformation mode with small relative density was included the overturning mode and compaction by seismic wave. To establish the performance-based design on reinforced soil retaining wall, it is necessary to consider the deformation mode that could happen adequately.