滨海矿区地应力与岩石力学参数随埋深的变化规律及其相互关系

The Variation Law of In-situ Stress and Rock Mechanical Parameters with Buried Depth in Coastal Mining Area and Their Relationship

三山岛金矿西岭矿区是我国首个进行滨海开采的金属矿区,研究埋深对该区域地应力和岩石力学性质的影响,对于滨海岩石工程开挖设计及灾害防控具有重要意义。通过对该矿区3个地质钻孔ZK88-21、ZK88-14和ZK94-2的不同埋深岩芯进行取样,获取埋深300~1900 m范围内的岩石标准试样。采用MTS815和声发射系统测试不同埋深岩石的力学参数与不同方向的声发射Kaiser效应点,进而获得不同埋深岩石的力学参数和地应力特征。以此为基础,分析滨海矿区不同埋深地应力、岩石力学参数及其之间的相互关系。结果表明:随着埋深的增加,滨海矿区岩石力学参数、自重应力、垂直应力、最大水平应力和最小水平应力均呈近似对数函数趋势增加,垂直应力的增幅逐渐小于自重应力。岩石力学参数与地应力大致呈对数关系,最大水平应力对岩石力学参数的影响大于最小主应力。埋深对岩石抗拉强度的影响大于其对抗压强度的影响。

The Xiling mining area in Sanshandao gold mine is the first coastal metal mining area in China.Therefore,it is of great significance for coastal rock engineering excavation design and disaster control to study the effect of the buried depth on in-situ stress,rock mechanical properties and their relationship.For this purpose,the standard rock specimen at 5 different buried depths ranging from 300 m to 1900 m were taken from the three geological drilling in this mining area,namely ZK88-21,ZK88-14 and ZK94-2.With the aid of MTS815,the mechanical parameters and acoustic emission Kaiser point in different directions of rock at different buried depths were tested,and the mechanical properties and in-situ stress of rocks were further obtained.On this basis,the in-situ stress,rock mechanics parameters and their interrelationships at different buried depths were analyzed.The results show that the mechanics parameters,self-weight stress,vertical stress,maximum horizontal stress and minimum horizontal stress have a logarithmic relationship with the buried depth,and the increase amplitude of vertical stress is gradually smaller than that of the self-weight stress with the increase of the buried depth.Similarly,the rock mechanics parameters are roughly logarithmic to the in-situ stress.Among them,the effect of the maximum horizontal stress on the rock mechanical parameters is greater than that of the minimum principal stress.In addition,the effect of buried depth on the tensile strength is greater than its effect on the compressive strength.