不同地应力测试方法在三山岛金矿2 005 m竖井建井区域的应用及其地应力分布规律研究

Application of different in-situ stress test methods in the area of 2 005 m shaft construction of Sanshandao gold mine and distribution law of in-situ stress

地应力对地下工程安全施工及长期稳定性是极其重要的。运用声发射法、非弹性恢复(ASR)法、水压致裂法对三山岛金矿西岭矿区2 005 m竖井工程勘察区域进行地应力测量,获取了其地应力分布规律及其异常区域,并分析了不同地应力测试方法的测试原理、适用条件及测试结果的差异性。结果表明:不同埋深水平最大主应力始终为第一主应力;当埋深增加到一定程度后,第二主应力发生转换,由最小水平主应力转变为垂直主应力;声发射法测量结果表明,第三主应力Kaiser效应点与ASR法、水压致裂法测试结果存在较大差异;分析了σ_(H)/σ_(V)、σ_(h)/σ_(v)、σ_(H)/σ_(h)随埋深的变化趋势(σ_(H)为水平最大主应力,σ_(h)为水平最小主应力,σ_(v)为垂直主应力),并对测试区域地应力异常区域进行了圈定。上述分析为竖井的设计、施工及长期稳定性提供了有效的数据支撑。

In-situ stress is highly important to the safe construction and long-term stability of underground engineering. Acoustic emission method, inelastic recovery method(ASR in short) and hydraulic fracturing method are applied to measure the in-situ stress in the area of 2 005 m shaft construction of Xiling of Sanshandao gold mine. The distribution law of in-situ stress and its abnormal area are obtained, and the principle and application conditions of different in-situ stress testing methods are briefly described. The results show that the horizontal maximum principal stress at different buried depths is always the major principal stress. Meanwhile,when the buried depth increases to a certain extent, the second principal stress changes from the horizontal minimum principal stress to the vertical principal stress. In addition, the results of AE measurement show that the Kaiser effect point of the third principal stress is different from those of ASR and hydraulic fracturing. Furthermore, the variation trends ofσ_(H)/σ_(V)、σ_(h)/σ_(v) and σ_(H)/σ_(h)with buried depth are analyzed, and the abnormal area of in-situ stress in the test area is delineated. The study could provide effective data support for the design, construction and long-term stability of the shaft.