桥基岸坡土体剪切强度特性试验研究

Shear strength characteristics of soils on bank slope of bridge foundation

为研究对某桥基岸坡稳定性起重要影响的粉质黏土的剪切强度特性和力学参数,对原状土进行了不同含水状态下的大型原位直剪试验。试验结果表明:原状土的变形破坏模式呈蠕塑性破坏。饱和和天然状态下原状土的抗剪断峰值强度参数分别为φ=17.1°,c=22.1 kPa和φ=20.6°,c=29.3 kPa;饱和状态下土的剪切强度参数比天然状态下降低20%左右;试验结果为该桥基岸坡稳定性分析计算提供取值依据。

Aiming at the problem of foundation stability evaluation of a bridge in disease remediation,in order to study the shear strength characteristics and mechanical parameters of the undisturbed soil of silty clay which plays an important role in the stability of the bridge foundation,the large-scale in-situ direct shear tests on the undisturbed soil under different water contents are carried out.The results show that the deformation failure mode of the undisturbed soil is creep plastic failure.Its shear peak strength parameters in the saturateds state are as follows:φ=17.1°,c=22.1 kPa,and those in the natural state are that φ=20.6°,c=29.3 kPa.The strength parameters of the saturated soil are reduced by about 20%compared with those in the natural state.The test results may provide a basis for the stability analysis and calculation of the bank slope of the bridge foundation.