高分子聚合物-剑麻纤维复合加固砂土抗压特性试验研究

Experimental Study on Compressive Characteristics of Sand Reinforced by Polymer and Sisal Fiber

针对砂土容易引发工程地质灾害问题,选用聚氨酯高分子聚合物和剑麻纤维复合加固砂土,对不同固化剂含量和纤维含量复合加固砂土的无侧限单轴抗压特性进行了评价,并运用电子显微镜(SEM)分析了复合加固砂土的微观力学机理。随着固化剂含量和纤维含量的增加,砂土的弹性模量、抗压强度和韧性均显著提高,试样破坏形态随纤维含量的增加由“花瓣状”向缝合线状过渡。聚氨酯通过提高土-土/纤维互锁力、土-纤维黏结力和土-纤维摩擦力,增强了纤维的加筋效果。

Sand widely distributed in engineering is easy to cause a series of engineering geological disasters due to its loose structure and poor engineering properties.In this paper,the unconfined uniaxial compressive characteristics of sand reinforced by polyurethane polymer and sisal fiber were evaluated,and the micromechanical mechanism of sand reinforced by different curing agent and fiber contents was analyzed by electron microscope(SEM).With the increase of curing agent content and fiber content,the elastic modulus,compressive strength and toughness of sand soil increases significantly,and the failure morphology of the sample changes from"petal-like"to suture line shape with the increase of fiber content.Polyurethane enhances the reinforcing effect of fiber by improving soil-soil/fiber interlock force,soil-fiber bonding force and soil-fiber friction force.