粘性土试样高度对抗拉强度的影响

Effect of specimen depth on the tensile strength of cohesive soils

针对粘性土抗拉强度测试问题,本文设计改装了土样拉伸试验仪,可完成单轴拉伸、巴西劈裂和轴向压裂三种抗拉强度试验。通过不同方法测定土体的抗拉强度,研究了试样高度对各方法强度测量值的影响及其规律。试验结果表明,试样高度对轴向压裂试验测试结果的影响最大,对巴西劈裂试验测试结果影响很小,几乎不影响单轴拉伸试验测试结果。轴向压裂试验中,抗拉强度测试值随试样高度h增大而减小,随衬垫直径增大而增大。巴西劈裂试验中,试样抗拉强度测试值随试样高度增大略有增大。

An apparatus for testing tensile strength of cohesive soil is developed,and it can realize different tension test methods including uniaxial tension test,Brazilian test and axial splitting test.The variations in tensile strength of soil with the change of specimen depth are investigated.The results of the tests indicate that the test results obviously varie with specimen depth in the axial splitting test,slightly in the Brazilian test,and none in the uniaxial tension test.In axial splitting test,the tensile strength of the specimens decreases with the increasing specimen depth,and increases with the increasing diameter of gasket.In the Brazilian test,the tensile strength of the specimens increases slightly with the increasing specimen depth.