中文摘要：

天然岩体在长期地质作用下会生成各种节理裂隙等不连续面，而地下工程结构的稳定性一般取决于这些不连续面的强度。在众多因素中，表面形态对岩石节理面剪切强度具有决定性影响。为了系统研究岩石节理面剪切强度的确定方法，把岩石节理面概化为一系列高度不同的微长方体凸起组成的粗糙表面结构，且微长方体凸起有剪胀破坏和非剪胀破坏两种模式。综合微长方体凸起破坏规律，应用概率密度函数描述节理面表面起伏分布的影响，建立了粗糙节理面随机强度模型，推导了节理面剪切强度理论公式，提出了节理面强度的随机评价方法。基于随机强度模型和评价方法编制Matlab计算程序计算自然粗糙节理面的剪切强度，并将计算结果与试验结果进行比较分析。研究表明：粗糙节理面随机强度模型综合了粗糙节理面表面形态和法向应力对节理剪切强度的影响机制，理论计算值与试验数据吻合良好，可以较好的评价粗糙节理的峰值剪切强度和残余剪切强度。该随机模型可作为进一步深入研究的重要基础，分析结构面的连续剪切过程，建立更完善的节理面强度模型。

英文摘要：

Jointed rockmass is involved in many civil engineerings. Correct assessment of the shear strength of rock joint surfaces is essential for such projects design. However, there are various factors to affect shear strength of rock joints. Among them, the surface shape of the structure plane is vitally important for its mechanical property because the surface shape affects the real area of contact and frictional status definitively. In this study, the rough joint surface is considered to be made up of a series of microcosmic rectangular-shaped asperities with different heights. There might be two failure modes of a rectangular asperity： a dilative failure mode and a non-dilative failure mode, although the rough joint surfaces show macroscopic shear-dilatancy failure in most cases. Based on them, the stochastic strength model of rough joint surfaces is established by applying the probability density function to describe the asperity height distribution. The shear strength is theoretically derived according to the proposed model. Direct shear tests on artificial rough joint surfaces are performed to verify the proposed stochastic model and its application method. The theoretical computations of stochastic model provide a good agreement with the obtained peak shear strength and residual shear strength from shear tests, which may serve as an effective approach for quantitatively estimating the peak shear strength and residual shear strength of rock joint surfaces.