砂土自由场地震响应的离心机试验研究

離心機模型試驗是研究巖土地震工程問題的有效手段。本文使用層狀剪切箱,通過干落法制備了均勻的砂土模型,進行了離心機振動試驗;觀測了振動過程中孔隙水壓力的發展,土體的加速度響應、側向變形以及豎向沉降。結果表明,土體的運動和變形與孔隙水壓力的發展密切相關,但離心機中的試驗現象和現場觀測的現象存在顯著區別。研究結果增強了對振動過程中土-水之間相互作用機理的理解,同時為自由場地震響應分析方法的驗證提供了基礎數據。 Centrifuge model test is an effective approach to study the issues related to geotechnical earthquake engineering. A centrifuge dynamic test was performed on a uniform free saturated sand ground model, which was prepared by the dry deposition method and contained in a laminar shear box. Acceleration, lateral displacement, vertical settlement as well as excess pore pressure were measured during the shaking event. It was observed that the motion and the deformation of soil body are closely associated with the development of excess pore pressure, but there exists remarkable difference between the phenomena occurring at the centrifuge and in the field. The results further our understanding of soil-water interaction under shaking, and provide the data for validating the analytical methods of the seismic response of free ground.