有机复合客土基材接触面剪切力学特性试验

Shear mechanical properties of contact surface of organic composite base material

摘要:

为研究高分子材料和接触面粗糙度对土-岩接触面剪切力学性能的影响,设计预制混凝土模块作为岩面相似材料,开展一系列改进型直剪试验,分析高分子材料和接触面粗糙度的影响规律,并结合扫描电镜试验深入揭示高分子材料的改良机制。结果表明,高分子材料主要通过提高黏聚力极大地改善基材土和接触面的剪切力学性能,掺量2%的基材试样黏聚力达41.76 kPa,提高了约3倍。掺量2%的不同接触面试样黏聚力提高了2~7倍；增大接触面粗糙度主要通过提高黏聚力增强接触面剪切力学性能,粗糙度为6.5 mm的不同接触面间黏聚力提升幅度为12.27~23.77 kPa,提高了0.4~3.9倍；对于平坦接触面和粗糙接触面,高分子材料对剪切性能的强化表现为两种不同模式；高分子材料与接触面粗糙度对接触面的剪切性能具有协同强化效应。

Abstract:

To investigate the influence of polymer material and contact surface roughness on the shear mechanical properties of soil-rock contact surface, we designed precast concrete samples as similar materials for rock surface and conducted a series of improved direct shear tests. The influence of organic polymer material and contact surface roughness was discussed. The improvement mechanism of polymer material was revealed by scanning electron microscope (SEM). Test results show that the polymer material could greatly improve the shear mechanical properties of the base soil and the contact surface by increasing the cohesive force, and the cohesive force of the substrate sample with 2% doping reached 41.76 kPa, which was increased by about 3 times. The cohesive force of different contact surface samples with 2% doping increased by about 2-7 times. The increase in the contact surface roughness could enhance the shear properties of contact surface by increasing the cohesive force, and the cohesive force of different contact surfaces with roughness of 6.5 mm increased from 12.27 kPa to 23.77 kPa, which was increased by 0.4-3.9 times. For flat contact surface and rough contact surface, the shear properties of polymer materials were strengthened in two different modes. The polymer material and the contact surface roughness had a synergistic strengthening effect on the shear properties of contact surface.