中文摘要：

岩石拉伸剪切破裂是一类特殊应力状态条件下的破裂形式，属于同时受垂直于破裂面的法向拉应力和平行于破裂面的剪应力作用的复合破裂模式。在研制的DSC-800电液伺服测控岩石拉伸剪切试验仪的基础上，进行了大量花岗闪长岩和砂岩的拉伸剪切试验，开展了配套的破裂断口三维激光扫描、扫描电子显微镜（SEM）、岩石物理力学性质试验、颗粒流离散元（PFC）数值模拟等相关试验，利用分形理论研究了岩石拉剪破裂面特征，研究了岩石拉剪-压剪全区破裂准则、剪切速率对岩石拉剪破裂强度的影响，采用颗粒流离散元研究了岩石拉剪破裂过程。研究结论如下：（1）岩石拉剪破裂面的宏观与微观分形维数即粗糙度随着拉应力的增加而增大；（2）岩石的微观断裂形式是拉伸破坏和剪切破坏的结合。当拉应力较小时，岩石的微观断裂形式主要表现为剪切破坏，并且随着拉应力的增加，岩石的拉伸破坏形式表现得更加明显；（3）岩石在拉伸剪切区的破裂拉应力与剪应力成线性负相关关系，在拉伸剪切应力区的岩石破裂线斜率比压缩剪切区大，岩石在拉伸剪切应力条件下比压缩剪切应力条件下容易破裂；（4）在岩石拉伸剪切条件下，剪切速率与剪切强度成非线性反相关关系，随着剪切速率的增加，岩石拉剪破裂面粗糙度增加；（5）建立了岩石拉伸剪切PFC数值试验模型，模拟了岩石拉伸剪切破裂过程中的力链演化以及剪切速率对拉剪破裂面粗糙度的影响，获得了与实验室试验一致的结果。

英文摘要：

Tension and shear fracture form of rock is under special stress state,that is under the normal tension stress perpendicular to the failure surface and shear stress parallel to rupture surface.Using the self-developed DSC-800 rock tension and shear apparatus with electro-hydraulic servo,we conducted plenty of tension and shear tests of granodiorite and sandstone;carried out corresponding three-dimensional laser scan of fracture surface,SEM,rock physical and mechanical properties tests,PFC numerical modeling tests,etal.Then studied the features of rock tension and shear fracture surface using fractal theory;got the whole fracture criterion of rock from tension-shear area to compression-shear area;analyzed the influences of rate of shear to rock tension and shear strength;studied the process of rock failure under tension and shear using PFC.Research conclusions are as follow：（1 ）Macro and micro fractal dimension（roughness）of the fracture surface increase with the increase of tension stress.（2）Micro fracture pattern of rock is combination of tension fracture and shear fracture.Micro fracture pattern is mainly about shear failure when tension stress is small;the tension failure is distinct gradually as tension stress increases.（3 ） Tension stress and shear stress have linear negative relationship in tension shear area.Line slope in tension shear area is greater than that in compression shear zone,and rock is more easy to fracture in tension shear area.（4） Under the condition of tension and shear,shear rate and shear strength have nonlinear inverse relationship.With the increase of shear rate,roughness of rock tension shear fracture surface increases.（5）Establish PFC numerical test model of rock under tension and shear stress to simulate force chain evolution in the process of rock fracture and the influence of shear rate on the roughness of tension shear fracture surface,and get the same results as laboratory tests.