地震作用下自由场中饱和砂土的应力-应变推导

水平自由场地震响应分析是岩土地震工程实践的重要内容之一。利用香港科技大学土工离心机上的双向振动台，进行了饱和砂土自由场在水平双向地震作用下的动力模型试验。根据应力和应变的定义以及达朗贝尔原理，由试验观测的土体加速度、位移和孔隙水压力数据直接推导得到不同深度处砂土的应力和应变，揭示了振动过程中饱和砂土的应力路径和应力-应变关系演化过程，以及与超静孔隙水压力发展的联系。

Derivation of stress and strain of saturated sand in free ground under seismic loading

Analysis of response of level ground subjected to earthquake is one of the most important problems in geotechnical engineering practice. By use of the bi-axial shaker installed on the geotechnical centrifuge at the Hong Kong University of Science and Technology, a centrifuge dynamic test was performed on a saturated sand ground model under a bi-axial earthquake loading. Based on definitions of stress and strain, and the D'Alembert's principle, stress and strain of soils at various depths were derived from the data of acceleration, displacement, as well as excess pore pressure measured in the test. The stress paths and stress-strain relationships of saturated sand during the shaking event, and their connection with development of excess pore pressure were revealed.