不同溶液下弱膨胀土的抗剪强度研究

Shear Strength of Weakly Expansive Soils in Different Solution

为了研究氯化钠溶液对膨胀土强度的影响,以宁明弱膨胀土为研究对象,对经不同浓度氯化钠溶液饱和后的试样进行直剪试验。试验结果发现,由于试样孔隙中氯化钠盐溶液的存在,改变了弱膨胀土的峰值和残余剪切强度,即经1 mol/L氯化钠溶液饱和的试样剪切强度小于蒸馏水饱和试样的剪切强度,氯化钠溶液降低了试样的黏聚强度和摩擦强度。认为造成上述结果的原因为,氯化钠溶液降低了位于剪切面上的颗粒与颗粒之间的作用力,使得相互阻碍作用降低,剪切面容易形成,表现为剪切强度降低。

In order to investigate the effect of Na Cl solution on shear strength of compacted weakly expansive clay,a series of direct shear tests were performed on Ningming weakly expansive clay saturated by Na Cl solution with different concentrations.The results show that Na Cl solution can change the shear strength of weakly expansive clay.The shear strength including cohesion and friction strengths decrease with increasing the Na Cl solution concentration.It is believed that the reasons for the above results are as follows:sodium chloride solution reduces the force between particles located on the shear surface induce the decrease of the mutual hinder.Thus the shear surface涝is easy to form?,which is manifested as the reduction of shear strength.