原状黄土抗拉强度试验方法研究

Study on the Test Method for Tensile Strength of Undisturbed Loess

利用由长安大学自主研制的土工拉压强度试验一体机,分别采用直接拉伸、径向压裂和轴向压裂三种试验对含水率为3%、5%、7%、10%、15%、18%的原状黄土进行抗拉强度测试。结果表明:三种试验测得原状黄土的抗拉强度整体较小,一般只有几千帕到几十千帕,其中直接拉伸试验测得的抗拉强度最大,其他两种方法测得的抗拉强度稍小;抗拉强度随着含水率的增大非线性减小,基本上为成负指数关系;直接拉伸试验值与间接拉伸试验值之间满足线性关系,可根据间接试验值推算出直接拉伸试验值。

Testing the tensile strength of undisturbed loess in moisture content of 3%, 5%, 7%, 10%, 15 %, 18% by using three methods of direct tensile test, radial and axial fracturing test respectively, the machine used was called the tensile and compressive strength test machine of the soil developed by Changlm University independently. The results showed that the tensile strength of undisturbed loess was overall smaller, generally only a few kPa to dozens of kPa, determined by three tests. The tensile strength measured by the direct tensile test was the maximum and others were smaller measured by radial and axial fracturing test. Tensile strength decreased non-linearly with water content increasing. The relationship between them is a negative exponential relationship basically. The tensile strength measured between direct tensile test and indirect tensile test was linear, so could be calculated the real tensile strenNh by the indirect tensile test.