循环荷载作用下饱和砂土的液化破坏

本文探讨了循环荷载作用下饱和砂土的极限平衡条件和液化破坏过程,给出了一个可用于饱和砂层地震稳定性分析的广义库伦公式。提出了一种方法:根据一个砂土液化试验记录的分析,给出饱和砂土的动力有效应力抗剪强度。为了工程应用的目的,建议把循环荷载作用下饱和砂土的破坏过程分为两个阶段,并把这两个阶段的起点作为饱和砂土的破坏准则。此外,也给出了饱和砂土液化破坏时破坏面上循环剪应力与循环荷载次数间的一般关系。

Liquefaction Failure of Saturated Sandy Soils under Cyclic Loading

The limit equilibrium condition and liquefaction failure process of saturated sandy soils under cyclic loading are discussed in this paper. As a result, an extended Coulomb's equation for analyzing the seismic stability of saturated sand layer is proposed, In accordance with the data of sand liquefaction test, an approach is advanced to determine the dynamic shear strength in the form of effective stress in saturated sandy soils. For practical engineering purposes, the liquefaction failure process of saturated sandy soils under cyclic loading is separated into two phases and the turns of these two phases can be regarded as the failure criteria of the sandy soils. In addition, the generalized relationships between cyclic shear stress on failure plane and the number of cyclic loading causing liquefaction of the sandy soils are also presented.