太原抽水蓄能电站关键部位地应力状态及其在枢纽工程布设中的应用  

In-situ stress state in critical areas of the Taiyuan pumped storage power station and its application in pivot project layout

作　　者：白金朋 董延安 甘俊 赵晓阳 李红利 柴宝 BAI Jinpeng;DONG Yan’an;GAN Jun;ZHAO Xiaoyang;LI Hongli;CHAI Bao(Beijing Engineering Corporation Limited,Beijing 100024,China;Shanxi Water Conservancy and Hydropower Survey,Design and Research Institute Co.,Ltd,Taiyuan 030024,Shanxi,China)

机构地区：[1]中国电建集团北京勘测设计研究院有限公司,北京100024 [2]山西省水利水电勘测设计研究院有限公司,山西太原030024

出　　处：《地质力学学报》2023年第3期375-387,共13页Journal of Geomechanics

摘　　要：采用水压致裂地应力测试技术,开展了山西太原抽水蓄能电站工程2个孔(孔深500 m和520 m)的地应力测试工作,获得了工程区关键部位地应力状态,分析了工程区的地应力水平、地下建筑布设方式和衬砌形式。结果表明:工程区最大水平主应力为10.98~18.09 MPa,最小水平主应力为6.79~11.32 MPa,垂直主应力9.61~13.57 MPa;与山西省南北两端“南高北低”地应力值相比,此次测值处于两者之间,与沁水盆地地应力场模拟值相比,测试结果基本一致;垂直应力介于最大水平主应力和最小水平主应力之间(SH>Sv>Sh),即测点的最大水平应力即最大主应力,且处于走滑型应力状态,其侧压系数Kav为0.92~1.09,反映出工程区构造作用不强烈;2个钻孔330~506 m范围内岩石饱和单轴抗压强度(Rb)为35.00~107.00 MPa,平均为63.79 MPa,岩石饱和单轴抗压强度与最大主应力比值(Rb/σm)为3.54~5.81,属于中—高应力水平;工程区最大水平主应力方向为NE 43°—NE 70.5°,平均为NE 59.5°,与区域震源机制解、GPS位移资料研究结果一致;从地应力方位考虑,地下厂房长轴线方向位于NE 29.5°—NE 89.5°之间,有利于厂房的围岩稳定;地下枢纽工程最大水头PH约为4.62 MPa,小于最小主应力值σ3(6.79~11.32 MPa),基于水力劈裂准则可知,岩体本身具有足够抵抗最大内水压力能力,输水隧洞采用钢筋混凝土衬砌,能够满足输水隧洞的稳定性。该研究成果可在抽水蓄能电站工程勘察、设计中推广使用。The hydraulic fracturing in-situ stress testing technology was used to test two boreholes(500-meter and 520-meter deep)at the Taiyuan pumped storage power station in Shanxi Province.The in-situ stress state of critical areas was obtained,and the ground stress level,underground building layout,and lining form in the project area were analyzed.The results show that the maximum horizontal principal stress ranges from 10.98 to 18.09 MPa,the minimum horizontal principal stress from 6.79 to 11.32 MPa,and the vertical principal stress from 9.61 to 13.57 MPa.Compared with the high and low in-situ stress values at the north and south ends of Shanxi Province,respectively,the measured values are between;Compared with the simulated in-situ stress field in the Qinshui Basin,the test results are basically consistent.The vertical stress values are between the maximum horizontal principal stress values and the minimum horizontal principal stress values(SH>Sv>Sh),which means the maximum horizontal stress at the measuring point is the maximum principal stress and is in the strike-slip stress state.Its lateral pressure coefficient Kav is between 0.92 and 1.09,reflecting that the tectonic action in the engineering area is not intense.In the range of 330–506 meters,the saturated uniaxial compressive strength of the two boreholes is betwwen 35 and 107 MPa,with an average of 63.79 MPa,and the ratio of the saturated strength to the Rbmaximum principal stress(/σm)is between 3.54 and 5.81,belonging to the medium–high stress level.The direction of the maximum horizontal principal stress in the project area is NE 43°to NE 70.5°,and the average is NE 59.5°,consistent with the regional focal mechanism solution and GPS displacement data.From the perspective of in-situ stress orientation,the average direction of the maximum principal stress in the engineering area is NE 59.5°,and the direction of the long axis of the underground powerhouse is between NE 29.5°and NE 89.5°,which is conducive to the stability of the surrounding rock of

关 键 词：水压致裂法 地应力 主应力方向 地下厂房轴线 输水隧洞衬砌 

分 类 号：P315.727[天文地球—地震学]