基于GSI的裂隙化岩体力学参数的确定

裂隙化矿岩体的力学强度特征和参数,主要受到岩块力学参数和岩体的节理裂隙参数的影响。为确定井下开采裂隙化矿岩体的力学强度参数,引入节理间距和节理面粗糙度系数(JRC)对地质强度指标(GSI)系统进行定量化的分级和参数取值,建立了定量化的GSI评价体系,综合采矿活动的影响因子,实现了裂隙化岩体力学强度参数的计算。以锌铜矿体的裂隙化矿岩体结构为研究对象,在进行的岩体工程地质调查基础上,取得了上下盘围岩的节理裂隙间距和节理结构面粗糙度系数,定量确定了上下盘围岩的裂隙化岩体强度力学参数。研究结果表明,运用定量化的GSI方法,可以实现裂隙矿岩体结构强度参数的确定,得到了锌铜矿体的上盘和下盘围岩的强度特征参数,其弹性模量分别为5.749 GPa和4.483 GPa,内聚力分别为3.126 MPa和2.772 MPa,内摩擦角分别为24.56°和23.08°。这些力学强度参数指标为裂隙矿岩体的采矿工程设计提供了基础参数。

Determination of mechanical parameters of fractured rock mass based on GSI

The strength parameters of fissured ore-rock mass are mainly influenced by the mechanical parameters of rock block and the characteristic parameters of the joints.In order to estimate the strength parameters of fissured ore-rock mass in underground mining,the quantitative Geological Strength Index(GSI) rock mass classification system is used,and the effect of mining activities is considered.The GSI system is quantified by using joint spacing and Joint Roughness Coefficient(JRC).The fissured ore-rock mass from Zu-Cu deposit in Tongkeng mining area is taken as the research object,the joint spacing and Joint Roughness Coefficient are obtained from the geological survey of rock mass,and the strength parameters of the hanging wall and the footwall rock are estimated.The results show that the GSI method can determine the parameters of fissured ore-rock mass.The strength parameters of the hanging wall and footwall rocks are obtained as follows: the modulus of elasticity,5.749 GPa and 4.483 GPa,respectively;the cohesions,3.126 MPa and 2.772 MPa,respectively;the angle of internal friction,24.56° and 23.08°,respectively.These mechanical parameters can be regarded as basic parameters for mining design.