宝兰铁路重塑黄土的轴向拉伸试验研究

为了揭示“宝兰重塑黄土”的抗拉特性，设计了一台测量精确、应用方便的土体抗拉试验装置，利用此装置对重塑黄土试件进行轴向拉伸试验，得到重塑黄土的应力-位移关系曲线、干密度和含水率对抗拉特性的影响规律。研究结果表明:重塑黄土抗拉强度随含水率的变化存在峰值，表现出两种不同的破坏形态，在塑限前主要受弹性变形控制，超过塑限后主要受塑性变形控制；重塑黄土的抗拉强度与干密度之间呈指数关系；重塑黄土的极限位移与干密度之间成线性关系。

Research on Axial Tensile Test of Remodeled Loess of Baoji-Lanzhou Railway

In order to reveal "the tensile properties" of the "baolan remolded loess" a soil tensile test device is designed with high measuring precision and application convenience. The axial tensile test is made on remolded loess sample by this device.It is obtained the stress and displacement curve of remolded loess samples and the influence law of dry density and moisture content on tensile properties. The research results show that tensile strength has a peak with the change in moisture content, which has two different failure pattern, and controlled mainly by the elastic deformation below the plastic limit, and by the plastic deformation above the plastic limit; The exponential relationship exists between the tensile strength of remolded loess and dry density and the limit displacement of remolded loess has a linear relation with the dry density.