基于GSI值量化和修正方法的岩体力学参数确定

为了准确确定岩体力学参数，通过综合分析多种地质强度指标(GSI)量化方法，提出了一种改进的GSI值量化和修正方法。首先，利用测线法估算结构面平均间距(d)和岩体块度指数(RBI)的改进型岩体块度率(RBR)，根据岩体三维结构面网络，获得岩体体积节理数(Jv)和岩体结构等级(SR)，然后采用上述参数和结构表面条件(SCR)及结构表面特性参数(Jc)进行了GSI值的定量化处理。为了克服GSI体系的缺点，考虑结构面产状和地下水对岩体力学性质的影响，提出了GSI值的修正方法和公式。以某铅锌矿体的矿岩体为例，根据改进的GSI值量化和修正方法及Hoek-Brown强度准则来确定矿岩体力学参数，通过与原位变形试验的对比分析，验证了该方法的精确性和可行性。该方法为从室内岩石力学试验合理地获取节理岩体力学参数提供了理论及实现的依据。

Determination of rock mass mechanical parameters based on quantification and correction method of GSI value

To accurately determine mechanical parameters of the rock mass, an improved method for the quantification and correction of GSI value was proposed on the basis of the comprehensive analysis on some quantification methods of GSI value. Firstly, by using the scan line method, this study obtained the average spacing of joints (d) and rock mass block rating (RBR) which was a new quantitative factor based on rock mass block index (RBI). The volumetric joint count of rock mass (Jv) and rock mass structure rating (SR) were acquired according to the three-dimensional (3D) joint networks of the rock mass. Then GSI values of rock mass were quantified by utilising these above parameters, surface condition rating (SCR) and the joint condition factor (Jc). To overcome the drawbacks of GSI system, the correction method and formula of GSI value were established by considering the effects of joint orientation and groundwater on the mechanical parameters of rock mass. The established method was applied in a lead-zinc mine as an example. According to the new quantification and correction method of GSI value and Hoek-Brown strength criterion, the mechanical parameters of the ore body, hanging wall rock and footwall rock were determined. The accuracy and the feasibility of this method were verified by the comparative analysis with in-situ deformation tests. This study provides the theoretical and practical basis to acquire mechanical parameters of jointed rock mass based on rock mechanical tests in the laboratory.