类软岩真三轴劈裂注浆裂隙扩展特征研究  

Fracture propagation characteristics of true triaxial splitting grouting in soft rock-like materials

作　　者：乔龙全 常聚才[1,2] 严良欢 齐潮 史文豹[1,2] QIAO Long-quan;CHANG Ju-cai;YAN Liang-huan;QI Chao;SHI Wen-bao(Key Laboratory of Safe and Effective Coal Mining Ministry of Education,Anhui University of Science and Technology,Huainan,Anhui 232001,China;School of Mining Engineering,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Coal Mine Safety and Efficient Mining Key Laboratory Jointly Established by the Ministry of Education,Anhui University of Science and Technology,Huainan,Anhui 232001,China)

机构地区：[1]安徽理工大学煤矿安全高效开采省部共建教育部重点实验室,安徽淮南232001 [2]安徽理工大学矿业工程学院,安徽淮南232001

出　　处：《岩土力学》2025年第3期833-850,共18页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.52174105,No.52104117);优秀科研创新团队项目(No.2023AH010023)。

摘　　要：地层软岩在劈裂注浆加固过程中裂隙扩展特征不明,经验化注浆参数设计不能有效加固围岩。为研究原位软岩劈裂注浆裂隙扩展特征,通过类软岩真三轴劈裂注浆试验,结合声发射参数特征,获得了不同主应力差与不同预制裂隙角度对裂隙扩展的影响规律,并采用理论分析与数值模拟方法对在三向应力下软岩试件劈裂压力差异及劈裂裂隙扩展转向机制进行讨论。结果表明:劈裂裂隙面与水平方向的夹角与其起伏程度随主应力差的增大而减小,劈裂过程中试件剪切裂纹占比随垂直压力增大而先减少后稳定;随着预制裂隙与垂直主应力夹角不断增大,初次劈裂压力先增大后减小,预制裂隙角度为0°与90°时,预制裂隙对劈裂裂隙扩展方向影响较小,预制裂隙为60°时,劈裂裂隙与预制裂隙发生贯通,预制裂隙角度为30°时,劈裂裂隙在浆液高压力的作用下转向交错;结合裸孔劈裂理论,对三向应力下劈裂压力差异与转向机制进行分析,软岩试件所受最大主应力与最小主应力的比值越大,其三向应力裸孔内劈裂的抗拉强度与巴西法测得抗拉强度的比值越小,劈裂裂隙初次劈裂扩展方向为裸孔环向压应力最小方向,扩展过程中会向预制裂隙两端应力集中处偏转,岩体应力分布变化是导致劈裂裂隙扩展转向主要原因。The fracture propagation characteristics of weak rock during split grouting reinforcement remain unclear,and empirically designed grouting parameters fail to effectively reinforce the surrounding rock.To investigate these characteristics in in-situ soft rock during split grouting,true triaxial split grouting tests were conducted on soft rock-like specimens.By analyzing acoustic emission parameters,we obtained the influence laws of varying principal stress differences and pre-existing crack angles on fracture propagation.Theoretical analysis and numerical simulation methods were employed to discuss the differences in splitting pressure and the mechanism of fracture propagation turning under triaxial stress conditions in weak rock specimens.The results reveal that as the principal stress difference increases,the angle between the fracture plane and the horizontal direction decreases,and the proportion of shear cracks in the specimen initially decreases and then stabilizes with increasing vertical pressure.As the angle between the pre-existing crack and the vertical principal stress increases,the initial splitting pressure first rises and then falls.When the pre-existing crack angles are 0ºand 90º,they have a minimal impact on the direction of fracture propagation.At a 60ºangle,the fracture propagates through the pre-existing crack.At a 30ºangle,the fracture turns and intersects under high grout pressure.Combining the bare hole splitting theory,the analysis of splitting pressure differences and turning mechanisms under triaxial stress indicates that the higher the ratio of the maximum to minimum principal stresses,the lower the ratio of the tensile strength in bare holes under triaxial stress to the tensile strength measured by the Brazilian test.The initial direction of fracture propagation aligns with the direction of the minimum hoop stress in the bare hole,and it deflects towards areas of stress concentration at both ends of the pre-existing crack during propagation.Changes in the stress distribution within

关 键 词：劈裂注浆 类软岩 真三轴 主应力差 预制裂隙 

分 类 号：TU451[建筑科学—岩土工程]