结合结构面统计的侧向岩石压力计算方法

岩体抗剪强度取决于结构面分布及其性质,侧向岩石压力的计算常用岩体等效内摩擦角参数,而边坡规范中岩体等效内摩擦角的取值难以反映实际岩体结构面分布及其性质的影响。为确定合理的支挡结构侧向岩石压力值,提出对现场岩体结构面性质包括产状、隙宽、迹长、间距、粗糙度进行统计,进而结合现场结构面统计的蒙特卡洛随机模拟结果和RMR地质评价系统,对岩体结构面进行定量评价。利用评价结果和Hoek-Brown准则拟合得到岩体等效摩尔库伦强度参数,由此计算侧向岩石压力。通过与现有方法进行对比发现,采用本方法得到的岩体等效内摩擦角计算所得的侧向压力更符合实际。

Calculation Method of Lateral Rock Pressure Combined with Structural Plane Statistics

The shear strength of rock mass depends on the distribution of discontinuity and its properties. The calculation of lateral rock pressure of retaining structure is usually based on the equivalent internal friction angle of rock mass. The value of equivalent internal friction angle of rock mass in the specification reflect the influence of the discontinuity's distribution and properties. In order to determine the equivalent internal friction angle of rock mass, this paper proposes a statistical simulation of discontinuity properties of the rock mass including the occurrence, gap width, trace length, spacing and roughness, And then combining the Monte Carlo simulation results based on the statistics of field discontinuity with the RMR geological evaluation system, a quantitative evaluation of the rock mass discontinuity is reached. Afterwards, using the Hoek-Brown criterion and the evaluation results, a equivalent molar coulomb strength parameters of the rock mass are obtained, and the lateral pressure of the rock mass slope is calculated. By comparing with the existing methods, it is found that the lateral pressure calculated by the equivalent internal friction angle of the rock mass obtained by the method is more realistic.