花岗岩体钻孔中结构面的分布规律——以深圳大亚湾花岗岩体为例

摘要

Discontinuities play a key role in the strength and stability of rock mass.During site selection of a project,granite is considered to be the ground or wall rock because of its high strength and integrality.Drillholes are the direct data of the target depth and reveal the rock mass during investigation.In the paper,Dayawan granite at Shenzhen is used as an example can to examine about the distribution of discontinuities in granite.Tectonic and secondary discontinuities are examined along drillhole depth.First,the discontinuities along drillhole and in the ground surface are contrasted.The occurrence distribution is similar because the same tectonic effect at the same site area.Secondly,the distance between two adjacent discontinuities along drillholes are analyzed (for direct effect RQD of drill cores).The discontinuity spacing and its frequency have evident power function relationship which is relevant to the RQD value.%结构面对工程岩体的强度及其稳定性起着关键作用.在工程选址时常会首先考虑花岗岩作为其地基或围岩,而钻孔揭露的是目标深度岩体最直接的数据.以广东深圳的大亚湾花岗岩体为例,结合地质背景,研究钻孔方向上结构面的分布规律.钻孔方向上花岗岩结构面主要为构造结构面和表生结构面.首先,对比沿钻孔方向花岗岩体中结构面与地表结构面的倾向与倾角,在同一场址区,受到同一构造作用影响,钻孔中与地表节理的产状分布类似.其次,研究沿钻孔方向结构面的间距(直接影响岩体的RQD值),通过间距分组和回归分析,发现结构面间距与其频数具有明显的幂函数关系,且该关系式与RQD值相关.