易溶盐对锰渣三轴剪切试验的影响

Effect of Soluble Salt on Triaxial Shear Test of Manganese Slag

锰渣因其含有易溶盐而在物理力学特性方面表现出盐渍土的特征。以脱盐前后的锰渣为研究对象,利用GDS三轴试验系统对其进行三轴剪切试验研究。结果表明:锰渣的应力-应变曲线可分为初始阶段、应变硬化阶段和破坏阶段;易溶盐流失后,脱盐锰渣更易出现应变软化现象。锰渣的应力-应变发展规律能较好地满足Duncan-Chang(邓肯-张)模型,脱盐锰渣的初始模量和极限强度均小于原锰渣。两种锰渣的孔压发展曲线存在一定差异,脱盐锰渣试件中孔隙水压力衰减的现象更显著。锰渣的破坏应力和抗剪强度参数随干密度的增大而增大,干密度对锰渣的黏聚力影响较大,对内摩擦角影响较小;随着易溶盐的流失,锰渣的强度和刚度均有所降低。

Manganese slag shows the characteristics of saline soil in physical and mechanical characteristics because that it contains soluble salt.In this study,the triaxial shear tests of original manganese slag and desalted manganese slag were carried out using GDS triaxial test system.The results showed that the stress-strain curve of manganese slag can be divided into initial stage,strain hardening stage,and failure stage.The desalted manganese slag was more prone to strain softening as the loss of soluble salt.The stress-strain development law of manganese slag can better meet the Duncan-Chang model.The initial modulus and ultimate strength of desalted manganese slag were both less than those of original manganese slag.There were some differences in the pore pressure development curves of the two kinds of manganese slag,and the attenuation of pore water pressure in the desalted manganese slag specimens was more significant.The failure stress and shear strength parameters of manganese slag increased with the increase of dry density.Dry density has a great influence on the cohesion of manganese slag but a small influence on the internal friction angle.After losing soluble salt,the strength and stiffness of manganese slag are reduced.