压剪作用下裂隙扩展过程渗流与应力耦合模型研究  

Seepage flow during crack propagation process and stress coupled model under compression-shear stress conditions

作　　者：赵瑜[1,2] 王超林[1,3] 万文[3] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]湖南科技大学岩土工程稳定控制及健康监测湖南省重点实验室,湖南湘潭411201

出　　处：《岩土力学》2016年第8期2180-2186,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51374257;No.50804060);教育部新世纪人才基金(No.NCET-09-0844);岩土工程稳定控制及健康监测湖南省重点实验室开放基金(No.E21619)~~

摘　　要：裂隙的剪胀特性及扩展演化规律对岩体的渗流特性具有重要影响。为揭示裂隙剪胀及扩展演化对岩体渗流的影响,基于残余强度提出了一种能较好描述岩石硬化-软化特性的全剪切本构关系;结合剪切变形与裂隙开度的关系,利用最小势能原理和立方定律,建立了压剪作用下考虑裂隙剪胀特性的渗流应力耦合模型;假定压剪作用下裂隙发生Ⅰ型扩展,提出了伴有翼型裂纹的渗流模型,该模型不仅考虑了岩石的剪胀特性,更反映了裂隙扩展过程渗流的演化规律。对不同裂隙粗糙度的剪切应力-位移曲线进行分析,全剪切本构模型表现出较高的拟合精度。在剪切应力-位移关系基础上,通过剪切渗流试验数据对压剪作用下渗流模型进行验证,结果表明,该模型能较好地描述岩体剪胀阶段渗透性演化规律。利用等效裂隙简化裂隙网络,并通过试验数据进行验证,证实了裂隙扩展过程渗流-应力耦合模型的准确性与适用性。The dilatancy and propagation of cracks under compression and shearing are essential to hydromechanical behavior of fractured rock masses.To explore the influence of dilatancy and crack propagation on seepage flow,a new shear constitutive model is developed to describe the features of the pre-and post-shear curves based on residual strength of rocks.Then,by combining the relationship between shear deformation and fracture aperture,a coupled stress-seepage model for fractured rock mass subject to shear dilation process is derived by the minimum potential energy principle and cubic law.In addition,a formulation for determining fracture aperture during crack growth process is obtained by assuming the initiation of mode-I cracks under compression-shear conditions.This model can not only consider shear dilation of rocks,but also imply the effect of crack propagation on the evolution of seepage flow.It is found that the newly developed shear constitutive model is suitable for shear displacement curves with different rough surfaces.A stress dependent seepage model is established by applying the shear constitutive model and is validated by existing coupled shear-flow tests,which is capable of predicting the changes in hydraulic properties of fractured rock masses under compression-shear stress conditions.It is noticed that the stress-seepage model is reliable to reflect hydromechanical behavior of crack propagation by applying the equivalent fracture to the representative of different fractures.

关 键 词：裂隙开度 裂隙扩展 渗透系数 剪胀 

分 类 号：TU451[建筑科学—岩土工程]