砂土与钢材接触面剪切特性试验对比研究

Comparative Study of Shear Test Between Sand and Steel

为了研究砂土与钢材接触界面剪切特性,对原有的及改装后的DSJ-2型电动四联等应变直剪仪上分别进行了砂土同钢材界面的单剪试验和直剪试验,并做了对比分析。研究结果表明:1)单剪试验下在法向应力50kPa、100kPa时,砂土与钢材界面的剪应力-剪切位移关系曲线呈非线性弹性理想塑性关系,在法向应力200kPa、400kPa时呈刚塑性关系。直剪试验下在法向应力50kPa、100kPa时,砂土与钢材界面的剪应力-剪切位移关系曲线呈非线性关系,在法向应力200kPa、400kPa时呈双曲线关系;2)提出了界面抗剪强度指标的经验换算公式(直剪试验下得到的界面抗剪强度指标乘以一个小于1的系数),以修正应用于设计的直剪试验结果。

In order to study the shear properties of the interface between the sand and steel, the result of a series simple shear test and direct shear test of interface between dry, saturated sand and smooth, rough steel on the DSJ--2 electric four-joint equal stress direct shear apparatus and after reffitted is constrastively analyzed. The result shows that the shear stess--shear displacement curve of interfaces presents misalignment elastic ideal plasticity relations when the vertical stress is 50,100kPa or presents rigidity-plasticity relations when the vertical stress is 200,400kPa with the simple shear test, the shear stess-shear displacement curve of interfaces presents misalignment relations when the vertical stress is 50,100kPa or presents hyperbolic curve relations when the vertical stress is 200,400kPa with the direct shear test. In addition, the experience reduction formula of contact surface shearing strength target（the interface shear strength index with the direct shear test multiplied by a factor less than 1）are proposed to revise the direct shear test result in design.