非饱和土的应力-含水率-应变关系试验研究

引入含水率,研究了非饱和土的强度和应力-含水率-应变关系.进行了非饱和土的强度和变形试验,模拟了实际工程施工期气压能够迅速消散而水压变化不大的特点;研究了强度随含水率的变化,建立了非饱和土总应力强度公式;研究含水率对非饱和土变形的影响,建立了引入含水率的实用非线性模型.算例分析表明了方法的合理性.引入工程中易确定的含水率,完全绕开了吸力,避免了吸力量测和计算的困难,为非饱和土理论成果难以实用化的问题提供了有效的解决途径.

Experimental study on stress-water content-strain relationship of unsaturated soil

Strength and stress-water content-strain relationship of unsaturated soil is studied experimentally. Firstly, strength and deformation tests are done, which simulate the project characteristic that pore air pressure dissipates very quickly and water pressure does not. Secondly, a total stress strength formula is suggested by researching the relationship between the strength and water content. Finally, a nonlinear model is presented on the basis of the relationship between the parameters under different values of constant water content. A case study shows that the model is reasonable. The use of the theories of unsaturated soil has been limited because of the difficulties in measuring and calculating suction. The presented approach, choosing water content which can be gained easily in project, can solves this problem effectually.