水力耦合作用下三维中空裂隙扩展模式与材料破坏强度的试验研究  

Experimental research on propagation mode of 3D hollow crack and material failure strength under hydro-mechanical coupling

作　　者：李邦翔[1] 朱维申[1] 杨磊[1] 虞松[2] 梅洁[1] 蔡卫兵 张强勇[1] 陈云娟[3] LI Bangxiang;ZHU Weishen;YANG Lei;YU Song;MEI Jie;CAI Weibing;ZHANG Qiangyong;CHEN Yunjuan(Geotechnical & Structural Engineering Research Center,Shandong University,Jinan 250061,China;School of Civil Engineering,Shandong University,Jinan 250061,China;School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]山东大学土建与水利学院,山东济南250061 [3]山东建筑大学土木工程学院,山东济南250101

出　　处：《中南大学学报（自然科学版）》2019年第5期1192-1202,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51509146,51579140,51609130);泰山学者工程专项经费资助项目(2017)~~

摘　　要：采用透明树脂类岩石材料制作含三维中空单裂隙试件,开展水力耦合破裂试验,研究三维裂隙起裂扩展模式,分析裂隙倾角和水压对裂隙起裂应力及试件破坏强度的影响规律。研究结果表明:三维中空裂隙的起裂和扩展模式与闭合裂隙相比差异显著,水力耦合下三维裂隙起裂扩展模式呈现低水压与高水压2种类型,水压升高对裂隙起裂、扩展具有显著的促进作用,并改变试件的破坏模式;随裂隙倾角增大,翼裂纹临界扩展长度逐渐减小,鱼鳍状裂纹的萌生时间呈后延趋势;水压对裂隙起裂应力和试件破坏强度的影响分别存在阈值,在达到阈值前,水压升高使起裂应力小幅度增大,而破坏强度逐渐降低;当水压超过阈值后,起裂应力与破坏强度均迅速降低;裂隙起裂应力和试件破坏强度均随裂隙倾角增大而呈先降低后升高的趋势,但起裂应力的变化幅度比破坏强度的变化幅度更大。The transparent rock-like resin material was adopted to manufacture specimens containing single 3D hollow crack.Then,hydro-mechanical coupling experiments were carried out to investigate the initiation and propagation modes of 3D hollow crack,and to analyze the influences of crack dip angle and water pressure on the initiation stress of crack and the failure strength of specimen.The results show that the initiation and propagation modes of 3D hollow crack are significantly different from those of the closed crack.Under the condition of hydro-mechanical coupling,the initiation and propagation of 3D hollow crack present two types of modes,i.e.,the low water-pressure type and the high water-pressure type.The increase of water pressure promotes significantly the crack initiation and propagation,which changes the overall failure mode of specimen.With the increase of crack dip angle,the critical growth length of wing crack decreases and the initiation moment of fin-like crack shows a hysteretic tendency.The influences of water pressure on the crack initiation stress and specimen strength have thresholds.Under the water-pressure threshold,the crack initiation stress increases slightly and specimen failure strength decreases gradually with the increase of water pressure.When the water pressure reaches or exceeds the threshold,both the crack initiation stress and specimen failure strength decrease significantly.Both the crack initiation stress and the specimen failure strength show a decreasing tendency at the beginning and then show an increasing tendency with the increase of crack dip angle.However,the variation amplitude of crack initiation stress is greater than that of the failure strength.

关 键 词：三维裂隙 水力耦合 起裂扩展模式 起裂应力 破坏强度 

分 类 号：TU45[建筑科学—岩土工程]