类砂质泥岩常规三轴浆压致裂起裂压力试验研究  

Experimental study on fracture initiation pressure of quasi triaxial slurry fracturing in similar sandy mudstone

作　　者：程桦[1,2,3] 刘向阳 曹如康[1] 王雪松 CHENG Hua;LIU Xiang-yang;CAO Ru-kang;WANG Xue-song(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan,Anhui 232001,China;School of Resources and Environmental Engineering,Anhui University,Hefei,Anhui 230601,China;Anhui Province Key Laboratory of Building Structure and Underground Engineering,Anhui Jianzhu University,Hefei,Anhui 230601,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]安徽大学资源与环境工程学院,安徽合肥230601 [3]安徽建筑大学建筑结构与地下工程安徽省重点实验室,安徽合肥230601

出　　处：《岩土力学》2022年第10期2655-2664,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51874005,No.51674006,No.51878005)。

摘　　要：为深入探究两淮矿区典型砂质泥岩劈裂注浆起裂机制,研制了常规三轴劈裂注浆试验装置,开展了类砂质泥岩浆压致裂起裂压力模型试验,基于试验结果分析了岩石强度与应力状态对注浆起裂压力、裂缝扩展形态影响规律,揭示了砂质泥岩劈裂注浆起裂机制。研究表明:起裂压力与岩石抗压强度呈正相关,且岩石抗压强度越高,劈裂路径越复杂;起裂压力对围压的敏感程度远高于轴压,且应力差Δσ=σ_(V)-σ_(H)越大,裂缝形态越规整;孔压三轴条件下,封闭裸孔段浆压致裂法确定的岩石抗拉强度值约为单轴抗拉强度的2.5倍。该研究结果可为今后类似岩层劈裂注浆参数设计与施工提供参考。Aiming at deeply explore the crack initiation mechanism of typical sandy mudstone splitting grouting in Huainan and Huaibei mining areas,a quasi triaxial splitting grouting test device was developed,and the model test of fracture initiation pressure of slurry fracturing in similar sandy mudstone was carried out.Based on the test results,the influence laws of rock strength and stress state on grouting initiation pressure and fracture propagation form were analyzed,and the splitting grouting fracture initiation mechanism of sandy mudstone was revealed.The results show that the initiation pressure is positively correlated with the rock compressive strength,and the higher the rock compressive strength,the more complex the splitting path.The sensitivity of initiation pressure to confining pressure is much higher than that of axial pressure,and the larger the stress differenceΔσ=σ_(V)-σ_(H),the more regular the fracture morphology.Under the triaxial condition with pore pressure,the rock tensile strength determined by slurry fracturing method in closed bare hole section is about 2.5 times of uniaxial tensile strength.The research results provide references for the design and construction of splitting grouting parameters in similar rock strata in the future.

关 键 词：砂质泥岩 常规三轴试验 劈裂注浆 起裂压力 模型试验 

分 类 号：TU91[建筑科学—建筑理论]