波浪作用下饱和砂土孔压发展规律试验研究

摘要

利用空心圆柱扭剪仪和动单剪试验仪分别对饱和砂土进行了循环耦合剪切和动单剪试验,研究比较两种不同方法下,饱和砂土内部孔隙水压力发展规律及其差异.结果表明,两种孔压发展规律具有显著差异,且分别可以采用传统孔压增长模型和幂函数关系加以描述;空心扭剪试验中,双向动荷载的幅值比值λ对孔压增长具有显著影响,但对归一化孔隙水压力发展模式没有显著的影响;动单剪试验中,存在循环振次临界转换值,该值决定了孔压增加随动剪应力的变化趋势.%Using the torsional shear hollow cylinder apparatus and dynamic simple shear test apparatus ,a set of bi-direc-tional cyclic loading and dynamic simple shear tests on saturated sand are conducted respectively in this paper .The de-velopment patterns of pore water pressure under two methods are analyzed and compared .The test results show that the development patterns which can be described by traditional pore water pressure development model and power function re-lationship are in significant difference .In bi-directional cyclic loading test ,the ratio of bi-directional dynamic load am-plitude (λ) has remarkable effect on pore-water pressure growth ,while the normalized pore-water pressure is not .In dy-namic simple shear test ,the increasing trend of pore water pressure along with dynamic shear stress depended on existing critical conversion value of cycle .