剪切速率对直剪试验的影响

Effect of Shear Rate on Direct Shear Test

在岩土勘察当中,土的抗剪强度是一个关键的指标。在计算挡土墙等工程建筑的土压力和工程建筑地基的承载力上,土的抗剪强度被频繁地应用。因此,正确且快速准确地测定岩土的抗剪强度在建筑工程中具有着至关重要的意义。室内土工试验是获取土的抗剪强度的一个重要手段。比如说,本次试验讨论的直剪试验就是其中之一。另外其他的还有比它更复杂的三轴压缩试验,以及无侧限抗压强度试验。而在室内试验当中,直剪试验因为其具有操作简单的特性,所以被广泛应用于工程勘察实践当中。但是在直剪试验过程中又会受到多方面因素的影响,包括剪切速率、土样密度与含水率、垂直荷重等。因而此次试验通过选取韶关某工地同一地层的粉质粘土进行固结直剪试验。对比试验分析发现,剪切速率对直剪试验的强度指标有着直接的影响。

In geotechnical investigation,the shear strength of soil is a key index.The shear strength of soil is often used to calculate the earth pressure of retaining wall and the bearing capacity of foundation.Therefore,it is very important to determine the shear strength of rock and soil correctly and quickly in construction engineering.Indoor geotechnical test is an important means to obtain the shear strength of soil.For example,the direct shear test discussed in this experiment is one of them.There are other more complex triaxial compression tests and unconfined compressive strength tests.In the laboratory test,the direct shear test is widely used in engineering investigation practice because of its simple operation.However,in the process of direct shear test,it will be affected by many factors,including shear rate,soil density and moisture content,vertical load and so on.Therefore,the direct shear test of consolidation was carried out by selecting the silty clay from the same stratum at a site in Shaoguan.It is found that the shear rate has a direct effect on the strength index of the direct shear test.