循环荷载作用下粗粒料变形特性的试验研究

Experimental study on the deformation characteristics of coarse-grained materials under cyclic loading

本文采用大型三轴试验机对粗粒料进行了不同应力条件下的动三轴循环加载试验,系统地研究了粗粒料在循环加载条件下的变形特性,并探讨了振次、围压、固结应力比和同步径向振动等因素对粗粒料变形特性的影响。试验结果表明,粗粒料的变形可分为往复变形和残余变形两部分,其中往复变形并不等同于传统意义上的弹性变形;固结应力比的增大使得粗粒料的往复轴应变和往复体应变减小,残余轴应变的增长速率随着固结应力比的增大而增大,而残余体应变的增长速率随着固结应力比的增大而减小;同步径向动应力比的增大,抑制了往复轴应变和残余轴应变的发展,而有利于往复体应变和残余体应变的发展。

The deformation characteristics of coarse-grained materials under cyclic loading are investigated by a series of large-scale cyclic triaxial tests,and the effects of cyclic loading times,confining pressure,consolidation stress ratio and synchronous radial vibration are discussed.The test results indicate that the deformation of coarse-grained materials is composed of reciprocating deformation and residual deformation,while the former is not the same as the elastic deformation.The reciprocating axial strain and reciprocating volumetric strain decrease with the increase in consolidation stress ratio,and the increase of consolidation stress ratio causes an increase in the growth rate of residual axial strain and a decrease in the growth rate of residual volumetric strain.The increasing of synchronous radial dynamic stress ratio restrains the development of reciprocating and residual axial strains and it is favorable to the development of reciprocating and residual volumetric strains.