大体积采空区岩体结构面聚类分布特征研究

广西北山矿业有限责任公司4#特大采空区具有体积大、形状不规则等特征。该采空区围岩发育有上甫—肯跃背斜和印支期、燕山期断裂构造,根据采空区围岩发育构造、岩层界线划分和泥灰岩、礁灰岩蚀变等特征,结合其岩石物理力学指标,划分了泥灰岩、白云岩、礁灰岩等3个工程地质岩组。采用测线法和体积密度法,开展了详细的采空区周边岩体工程地质条件现场调查。基于现场调查数据,通过结构面聚类分析,得出了结构面分布的几何参数概率特征,建立了主优势结构面倾向为52°和300°及主优势结构面倾角为75°的正态分布。分析计算结果显示:该模型可以有效的描述4#采空区节理产状分布特征。

DISTRIBUTION CHARACTERISTICS OF ROCK STRUCTURAL PLANES AT LARGEM INE GOAF IN GUANGXI PROVINCE

The 4# mine goaf in GuangxiBeishan mining Co. L td. is large and irregular in the form. The geological structure of surrounding rocks at the goaf is the anticline structure of Shangfu - Kenyue and the fracture of Indo - Chinese epoch and stage of Yanshan. Besides above structure character of the surrounding rocks, The paper further p resents the rock strata boundary and alteration of the marl and reef limestone in the goaf, aswell as the rock physi2 cal and mechanical indexes. Therefore, the paper classifies three engineering geology group s of rock mass. They are marlite, dolomite and reef limestone. The detailed field investigation of surrounding rockswas carried out by the methods of scan line and bulk density to show the comp rehensive condition of rock engineering geology. Based on the field investigation result, the geometrical parameters for the distribution ofmine goaf structural p laneswere ob2 tained using the cluster analysis. Characteristics of geometrical parameters p robabilitywas obtained about the struc2 tures p lanes. The normal distribution function model wasworked out. The 52°and 300°dip directions of the two p rimary dominant structure p lanes and the 75°dip angle of the p rimary dominant structure p lanes. The results show that thismathematicalmodel can effectively stimulate the joint and fissure distribution in the 4# mine goaf.