黄岛地下水封油库地应力场及地质构造作用分析

摘要

初始地应力场对地下洞室围岩稳定性影响十分显著,但由于地质条件的复杂性,通过单一方法得到的地应力场可靠性不高.以黄岛地下水封洞库工程为例,分析了研究区区域地质构造背景及近场断裂构造;通过水压致裂法进行了地应力测试,得到最大主应力方向主要集中在 NWW 向,优势方向为N73°W;通过地质构造分析法分析了研究区地应力场,探讨了区域构造运动历史对研究区现今构造应力场的影响,认为最大主应力方向为 NW—NNW.构造分析法与水压致裂法所得最大主应力方向大致均为 NW,但存在一定偏差;主要原因可能是研究区地质构造复杂,受构造变形边界条件影响,派生的局部应力场发生偏转.这表明,在分析地应力场时应结合区域地质构造作用分析及实测地应力进行综合评价.研究结果对于地应力场的综合确定方法具有一定参考价值.%The initial in-situ stress field has significant influence on the stability of surrounding rock of underground carven.Nevertheless,the in-situ stress field result obtained by a single method is usually not of high reliability because of the complexity of geological conditions.This paper takes the Huangdao underground water-sealed cavern as example and analyzes its regional tectonic background and near-field faults.The in-situ stress field is tested by hydraulic fracturing method.The maximum principal stress is obtained.Its directions are is mainly oriented NWW.Its advantage direction is N73°W.The stress field of study area is analyzed by geological structure analysis method.The impact of regional tectonic history on present tectonic stress field of study area is discussed.It is found that the maximum principal stress direction is NW~NNW.The maximum principal stress directions obtained by construction analysis and hydraulic fracturing method are roughly NW.But there is a certain bias.The main reason is probably due to the fact that the geological structure of research area is complicated and affected by the boundary conditions of tectonic deformation.Thus,the derived local stress field is deflected.The results suggest that the comprehensive evaluation of regional geological structure analysis and in-situ stress test should be used for stress field analysis.The result has a certain reference value for the comprehensive determination of stress field.