2019 Volume 75 Issue 1 Pages 15-34
1/30-scaled static centrifuge model tests and an elastic FE analysis were conducted to investigate the seismic behavior of buried RC-pipe, FRPM-pipe and box-culvert. In the tests, distributions of normal and tangential earth pressures acting on the surfaces of the three types of model culverts, as well as those of bending strains produced in their walls were precisely measured during cyclic simple shear deformation of the model ground. Test results showed that the tangential earth pressures acting on the culverts were almost null in any case. Numerical results of the FE analysis in which slip and separation at the culvert-ground interface were allowed showed good agreement with the test results. However, the prediction from the current seismic design standard for buried sewer culverts using seismic deformation method based on spring model contradicted the test and numerical results in both earth pressure and bending moment distributions. An analysis using continuum models based on elastic theory clarified that the seismic deformation method has theoretical defects in predicting the earth pressure. Therefore, the FE method used in this study was proposed as a new seismic resistant design method of buried culverts. Earth pressure on and bending moment of the three types of the sewer culverts were calculated by both the proposed design method and the current design standard under the conditions specified in the design manual, confirming that these two methods generate considerably different results. The proposed design method considers the soil-structure interaction properly and simulates well both the test results and damage to buried culverts observed in the past earthquakes, while the current design standard does not. Therefore, the proposed design method is recommended to be used instead of the current design standard based on the problematical seismic deformation method.