水泥改良泥质板岩粗粒土的静力特性

Static mechanical properties of argillaceous slate coarse-grained soil improved by cement

针对泥质板岩粗粒土,通过大型静三轴压缩试验研究未改良土样和水泥改良土样的轴向应力-轴向应变关系、体积应变-轴向应变关系、抗压强度、内摩擦角、黏聚力和弹性模量等,根据试验结果对水泥改良土和未改良土的力学性质进行比较。研究结果表明:水泥改良土和未改良土均具有应变软化性和剪胀性,改良土的应变软化性和剪胀性均比未改良土的显著;水泥改良土的最大体积压缩应变、与最大体积压缩应变对应的轴向应变均比未改良土的小,而残余体积膨胀变形比未改良土的大;水泥改良土破坏时变形比未改良土的小;与未改良土相比,水泥改良土的抗压强度、黏聚力和弹性模量均显著提高,线弹性变形范围也显著扩大,但内摩擦角的变化不大;水泥改良效果良好,水泥改良提高了泥质板岩粗粒土的力学性能。

Large scale static triaxial compressive tests were carried out to study the mechanical properties of argillaceous slate coarse-grained soil and the argillaceous slate coarse-grained improved by cement.Axial stress-strain relation,volumetric strain-axial strain relation,compressive strength,internal fraction angel,cohesion and elastic modulus of soil samples were obtained by the tests.Comparisons of test results between the improved soil and the unimproved soil were conducted.The results show that the soil improved by cement as well as the unimproved soil has mechanical properties of strain softening indicated by the axial stress-strain relation and dilatancy indicated by the volumetric strain-axial strain relation.Both the strain softening and dilatancy of the improved soil are more remarkable than those of the unimproved soil.The maximum compressive volumetric strain of the soil improved by cement and the axial strain corresponding to the maximum one are smaller than those of the unimproved soil,while the residual volumetric dilatancy of the soil improved by cement is larger than that of the unimproved soil.The failure strain of the improved soil is smaller than that of the unimproved soil.Compared to the unimproved soil,the compressive strength,the cohesion,the elastic modulus and the range of linear elastic deformation of the improved soil are enhanced significantly,while there is not much change to the internal fraction angle.As the mechanical properties of the argillaceous slate coarse-grained soil are improved by cement,the effects of the soil improvement are good.