含水率对砂岩渐进破裂过程影响的试验研究  

Experimental Study of the Effect of Moisture Content on Progressive Failure Process of Sandstone

作　　者：唐鸥玲 李天斌[1] 陈国庆[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川610059

出　　处：《实验力学》2016年第4期503-510,共8页Journal of Experimental Mechanics

基　　金：国家自然科学基金重点项目(41230635)

摘　　要：为了研究含水率对砂岩渐进破裂过程的影响,采用MTS-815岩石力学试验系统,考虑不同围压及含水率条件下砂岩的三轴试验,对其渐进破裂坏过程进行试验研究,分析不同含水率条件下砂岩的渐进破裂指标及其扩容特性的演化规律。研究结果表明,含水率对砂岩的渐进破裂过程存在促进作用;随着含水率的增加,砂岩的闭合应力、起裂强度、损伤强度和峰值强度均逐渐减小;且当砂岩饱水系数在0.7左右时,岩石损伤强度和峰值强度减少量超过20%;砂岩含水率对岩石强度的弱化作用较明显,而砂岩含水率的变化对扩容速率影响不明显,但随着含水率的增大,岩石压缩极限减小,扩容提前发生。In order to study the influence of different moisture contents on progressive failure process of sandstone,MTS-815 rock mechanics test system was adopted.Taking into account the different confining pressures and different moisture contents of sandstone,three-axis experiment was carried out to experimentally study its progressive failure process. The rupture index and dilatancy characteristics of sandstone were analyzed under different moisture contents condition.Experimental results indicate that moisture content has a promoting effect on progressive failure process of sandstone.Along with the increase of moisture content,the closure stress,initiation strength,damage strength and peak strength of sandstone all decrease.When the saturated coefficient of sandstone is about 0.7,both damage strength and peak strength of rock reduce more than 20%.Moisture content has a significant effect on rock strength weakening,while there is a little effect on dilatancy rate.But along with the increase of moisture content,rock compression limit decreases and the dilatancy point appears in advance.

关 键 词：含水率 岩石渐进破裂 破裂指标 扩容特性 

分 类 号：TU452[建筑科学—岩土工程]