断层构造近场地应力分布规律研究

Law of Geo-stress Distribution in the Vicinity of Fault Zone

通过分析几个典型断层构造近场水压致裂法地应力实测案例,结合构造地质力学及特性,得出近场断层构造地应力量值和方位主要受构造的空间分布、运动机制及其岩性影响的结论。一般而言,地应力量值在沿断层埋深方向上有不同梯度的分带,这与断层构造的剪切破裂形成机制及其影响带内岩性有关;最大水平主应力方位受断层构造的空间分布及运动机制影响,大致呈现与断裂走向平行或大角度斜交,甚至垂直的规律。分析断层构造近场地应力的分布有助于工程区岩体稳定性的科学评价,为工程选址提供依据。

／By analyzing cases of geo-stress measurement through hydro-fracturing method near typical engineering fault zones, and based on tectonic geomechanics, we conclude that the geo-stress near fault zone is mainly influenced by the space distribution, movement mechanism and lithology of the fault zone. In general, geo-stress value varies along the depth direction of the fault because of the shear fracture mechanism and the lithology of the affected zones. Furthermore, influenced by space distribution and movement mechanism of the fault, the orientation of maximum horizontal principal stress is almost parallel to or cross at a big angle with, or even vertical to the fault structure＇ s strike direction. Analysis on the distribution of geo-stress near the fault structure is contributive to the scientific assessment of engineering rockmass stability and the selection of project location.