基于GSI指标确定节理岩体的峰值和残余强度

Determination of Peak and Residual Strength of Jointed Rock Masses based on GSI System

岩石的地质强度指标GSI广泛应用于节理岩体的强度参数计算。首先采用定量化的GSI系统确定岩体的峰值强度参数,通过对峰值GSI值进行折减,得到残余地质强度指标GSIr,计算残余强度参数,根据Hoek-Brown强度准则计算节理岩体的抗压及抗拉强度。然后针对四种典型岩体做了峰值和残余强度的计算分析。最后,利用适用于岩石类脆性材料的弹塑性损伤模型,分析模拟残余强度对地下开挖围岩塑性区范围的影响。

The rock geological strength index GSI is widely used in the calculation of strength parameters of jointed rock masses. Firstly, the peak strength parameters of the rock masses are determined by quantitative GSI system. The residual geological strength index GSIr values can be got through the reduction of peak GSI values, then the residual strength parameters can be got. The compressive and tensile strength of the jointed rock masses are calculate based on the Hoek-Brown strength criterion. Then, the peak and residual strength of four typical rock masses are calculated and analyzed. Finally the impact of the residual strength on the range of the surrounding rock plastic zone of the rock is analyzed and simulated by the elastoplastic damage model which is suitable for the brittle materials of rock.