水平循环荷载作用下弱化饱和黏土的p-y曲线

p-y Curve of Weakening Saturated Clay Under Lateral Cyclic Load

为研究平台桩基础在长期循环荷载作用下的弱化特性,探讨孔隙水压力的变化对土体强度的影响。利用现有孔隙水压力的发展模型,建立长期循环荷载作用下土体残余抗剪强度模型,运用API规范中的p-y曲线公式,建立评价弱化后土体横向承载力的方法。分析表明:土体孔压随荷载循环次数的增加而逐步上升,且荷载越大,土体孔压上升越快;通过与试验中测得的孔隙水压力对比发现,HYDE等建立的孔压发展模型与试验中测得的孔隙水压力变化较为吻合,说明该模型能很好预测循环荷载下孔隙水压力的变化。

In order to study the weakening features of a platform foundation under the long-term cyclic loading,the impact of changes of pore pressure on the soil strength is discussed and existing pore pressure development model is used to establish the soil residual shear strength model under the long-term cyclic loading.The results of the model is inserted into the p-y curve formula recommended by the API as the soil shear strength after weakening,so that the method to evaluate the lateral resistance of the soil after weakening is obtained.The analysis shows that the pore pressure increases gradually with the increased number of loading cycles.As the increase of the load,the pore pressure rises more quickly.By comparing with the pore water pressure measured in the test,it is found that the pore pressure development model established by HYDE is in good agreement with the pore water pressure measured in the test.This model can well predict the change of pore water pressure under cyclic loading.