基于PFC-FLUENT联合开展岩体水力劈裂细观机理分析

为研究岩体水力劈裂的致灾过程,揭示水力劈裂细观机理,采用VB编译平台,实现PFC、SURFER、GAMBIT、FLUENT商业软件的调用,并依托FORTRAN编译子程序实现软件间数据信息交换及特定功能,完成岩体水力劈裂三维分析平台的构建。随后,利用该平台建立与文献中相同的岩体水力劈裂圆筒模型,并与试验结果比对,验证了该平台研究岩体水力劈裂的可行性。最终,以某一输水隧洞为例,依托该平台开展输水隧洞裂纹扩展研究,分析高内水压下围岩裂隙萌生、扩张、延伸、贯通的破坏过程。结果表明:该平台能较精细地揭示隧洞衬砌水力劈裂过程并动态获取相应裂隙流场分布特征,针对该隧洞模型,衬砌外围岩压力大于0.6 MPa时方能确保当前高压内水作用下隧洞衬砌安全。

Microscopic Mechanism Analysis of Hydraulic Fracturing of Rock Mass Based on Coupled PFC-FLUENT Method

In order to study the disaster-causing process of hydraulic fracturing of rock mass and reveal the microscopic mechanism of hydraulic fracturing,three-dimensional analysis platform for hydraulic fracturing of rock mass is performed,using VB compilation platform,which can finish the implementation of different business soft-wares including PFC,SURFER,GAMBIT and FLUENT,and achieving data information exchange and specific functions between different software based on FORTRAN.Subsequently,the reliability of the platform is verified by establishing the same hydraulic fracturing cylinder model of rock mass as in the literature and comparing with the test results.Finally,depending on the platform,a research on crack growth of outlet tunnel is carried out to analyze the failure process of crack initiation,expansion,extension and penetration in surrounding rock under high internal water pressure.The result shows that the platform can accurately reveal the hydraulic fracturing process of tunnel lining and dynamically obtain the distribution characteristics of corresponding fracture flow field.For this tunnel model,only when the pressure of the surrounding rock outside the lining is greater than 0.6MPa can the lining of the tunnel be safe under the action of the current high-pressure internal water and this conclusion has important guiding value for the design of outlet tunnel.