加卸载作用下裂隙岩芯渗透性变化规律研究

发布时间：2018-02-25 16:21

本文关键词： 安全工程裂隙岩体渗透率粗糙度应力历史流固耦合　出处：《安全与环境学报》2017年01期 　论文类型：期刊论文

【摘要】：针对光滑平行板裂隙加载渗流规律难以准确反映实际工程裂隙岩体卸荷渗流特性的问题,利用水力压裂方法制作了天然岩芯裂隙,开展了裂隙试件受轴压、围压加载和卸载作用的渗流试验,并将裂隙试件的CT扫描图像导入ABAQUS软件,对粗糙裂隙受载时的应力和变形规律进行了数值模拟。结果表明:裂隙面的法向应力是影响裂隙渗流的主要因素;在加载阶段,粗糙裂隙面受载产生接触应力致使接触部分产生变形和破坏,裂隙接触刚度增大,裂隙宽度非线性减小,渗透率降低速率越来越小;在卸载阶段,弹性变形逐步恢复,裂隙宽度缓慢增加,渗透率先缓慢增大,当载荷卸到一定值后,在孔隙压力作用下裂隙张开、渗透率突然增大。研究结果表明了粗糙裂隙与光滑平行板裂隙对载荷敏感性不同的机理,反映了实际工程裂隙岩体卸荷渗流特性。
[Abstract]:In view of the problem that the seepage law of smooth parallel plate crack loading is difficult to accurately reflect the unloading seepage characteristics of practical engineering fractured rock mass, the natural core fractures are made by hydraulic fracturing method, and the fracture specimen is subjected to axial compression. The seepage test of confining pressure loading and unloading action, and the CT scanning image of fracture specimen were imported into ABAQUS software. Numerical simulation of stress and deformation law of rough fracture under loading is carried out. The results show that normal stress of fracture surface is the main factor affecting fracture seepage, and in the loading stage, The contact stress caused by the load on the rough fracture surface causes the deformation and failure of the contact part, the contact stiffness of the crack increases, the width of the crack decreases nonlinear, the rate of permeability decreases, and the elastic deformation recovers gradually in the unloading stage. The crack width increases slowly, the permeability increases slowly, and when the load is discharged to a certain value, the crack opens under the action of pore pressure. The results show that the mechanism of the difference between the rough fracture and the smooth parallel plate fissure is different to the load sensitivity, which reflects the unloading seepage characteristics of the actual engineering fissured rock mass.
【作者单位】：辽宁工程技术大学力学与工程学院;
【基金】：国家自然科学基金项目(11072103) 辽宁省高等院校优秀人才支持计划项目(LR2011008) 辽宁工程技术大学研究生创新项目(5A2014014-01)
【分类号】：TU45

【相似文献】