聚丙烯纤维膨润土的试验研究和机制分析

Experimental study and mechanism analysis of polypropylene fiber-reinforced expansive soil

为研究聚丙烯纤维的含量对膨润土强度和变形的影响,本文通过等向压缩试验、常规三轴压缩不排水剪切试验和固结快剪试验等对不同质量掺量(0、0.25%、0.5%)的聚丙烯纤维膨润土进行研究。试验结果表明:对于某一膨润土,当纤维选择合适,纤维加筋可以有效抑制膨润土体的变形,并存在一个最优加筋率;纤维的含量对膨润土的强度有一定的影响,在相同围压下,纤维掺量在0.25%左右对土体的增强效果最好;纤维主要增加的是土体的黏聚力,对土体的内摩擦角影响不大。

The aim of this research was to investigate the behavior of polypropylene fiber-reinforced expensive soil. The experimental study consisted of isotropic compression tests,undrained triaxial compression tests and direct shear tests.Tests were carried out on a uniform expensive soil reinforced with randomly distributed polypropylene fibers（ 0,0. 25% and 0. 5% by weight,respecturely）. Experimental investigation demonstrated that fiber inclusion increases the strength of expensive soil,and there is a best strength for expensive soil under the same confining pressure with 0. 25% polypropylene fiber contents by weight.In addition,fiber-reinforcement makes a great differenceson cohesion but little on the friction angle for the tested expansive soil.