2024 年 10 巻 39 号 p. 1491-1496
In this study, the impact of the building settlement due to the loss of foundation bearing capacity during soil liquefaction on buried pipelines was experimentally investigated. The forced displacement tests simulating the building settlement were conducted on full-scale physical models of buried service lines that connect distribution mains and buildings, including those for potable water and natural gas. Both complete liquefied and non-liquefied conditions of the soil surrounding the pipelines were simulated. During these tests, the longitudinal strains, deflection, and possible leakage of pipelines were monitored. The results showed that different conditions of surrounding soil led to different strain distribution and deflection along the pipeline. Yielding of the pipe material and the pulling out of the pipeline from the joint were caused if the settlement was large enough. Local buckling of the pipe near the loaded end was induced in non-liquefied cases due to the combination of forced displacement and soil reaction. Besides, the flexibility of pipes and the strength of joints were found influential on the resilience to the aforementioned damage modes. These findings provide better understanding of the resistance performance of buried pipelines against liquefaction-induced displacement and are beneficial to the seismic mitigation of lifelines.
