摘要
节理糙率系数(JRC)是影响岩石节理剪切特性的重要因素，准确估算节理糙率系数是岩石工程中具有挑战性的课题。现有的JRC评价方法如经验比较法和统计参数法都存在一些尚未解决的缺陷。针对现有基于抗剪强度反演方法的不足，提出了一种新的JRC估算方法。首先，在粘结颗粒法(BPM)生成的数值岩石样品中建立了10个标准粗糙度节理其次，标定了完整岩石和节理的微观参数，并进行了不同正应力下节理试件的直剪试验。最后，提出了高相关性条件下抗剪强度与JRC的经验关系式。结果表明，改进的光滑节点模型(MSJM)比光滑节点模型(SJM)更能模拟粗糙节点的力学性能将目标节点抗剪强度按对应关系代入，可以方便地求得节点沿剪切方向的JRC。此外，还得到了10个标准粗糙度节理剖面在左右(FRTL)剪切方向下的JRC值。通过对文献中9个目标节点JRC的估算，表明本文提出的新方法能较好地反映粗糙度的方向性，便于应用。
Abstract
The joint roughness coefficient (JRC) is an important factor affecting the shear properties of rock joints, and its accurate estimation is a challenging task in rock engineering. Existing JRC evaluation approaches such as the empirical comparison method and the statistical parameter method have some unresolved defects. In this study, a new method is proposed for JRC estimation to overcome the deficiencies of existing approaches based on back calculation of shear strength. First, the 10 standard roughness joints are established in numerical rock samples generated by the bonded particle method (BPM). Secondly, the microscopic parameters of the intact rock and joints are calibrated, and a series of direct shear tests of joint samples are carried out under different normal stresses. Finally, the empirical relationships between shear strength and JRC are proposed under high correlation conditions. The results show that the modified smooth joint model (MSJM) is proved to better simulate the mechanical properties of rough joints than the smooth joint model (SJM). When the shear strength of target joint is substituted in the corresponding relationship, the JRC of joint along the shear direction can be conveniently obtained. In addition, the JRC values of 10 standard roughness joint profiles under shear direction of from right to left (FRTL) are obtained. By estimating the JRC of 9 target joints in the literature, it can be seen that the new method proposed in this paper can well reflect the directionality of roughness and it is convenient to apply.
NETL
NSTL
Hindawi Publishing Group