循环荷载下饱和粘土强度等效计算探讨

Discussion on Equivalent Calculation for Shear Strength of Saturated Clay under Cyclic Loading

摘要:

饱和粘土在不排水循环荷载作用下强度会发生衰减,建立在粘土地基上的建筑物和填土道路在地震过程中有时会遭受破坏.本文在超固结粘土不排水强度计算的基础上,引入循环荷载作用损伤因子,提出循环荷载作用下饱和粘土强度计算方法以及参数的确定方法.同时,分析了循环荷载作用下再固结系数对粘土强度增长的影响.通过试验验证,所提出的方法是合理的.该方法为循环荷载作用下粘土地基的强度和稳定性预测提供有效的途径.

Abstract:

The undrained strength of saturated clay will decrease during undrained cyclic loading. Sometimes serious damages to structures sited on clay layers and filled road pavements are occurred in earthquakes. In this paper, based on the over-consolidated undrained strength, a cyclic loading-induced degradation parameter is introduced, and the calculation methods for cyclic shear strength of saturated clay and the parameters are proposed. Meamwhile, the effect of reconsolidation index to the post cyclic shear strength increment is analyzed. According to the undrained cyclic triaxial tests, the proposed method is verified available. The method will be effective to predict the cyclic shear strength and stability of clay layers.