【摘要】 为分析水封式大连地下石油储备库洞室群围岩稳定性及渗流场特征,首先基于现场地应力实测结果的回归分析,利用Fish语言编写函数,反演初始地应力场。其次,采用三维离散元程序3DEC生成三维节理网络模型,反演库区初始渗流场的各向异性特征。最后,利用应力与渗流耦合模块实施开挖仿真计算,获取围岩应力场、位移场变化特征。考虑平行、垂直层理面不同材料特性,基于带有抗拉的Mohr-Coulomb强度储备型点安全系数,定量评价洞室群的稳定性。借鉴国外水封效果评价标准,分别从地下水位线和垂直水力坡降2个方面,分析渗流场变化特征。研究表明:在洞室周边平行层理面点安全系数为1.02～1.25,垂直层理面点安全系数为1.95～2.00。在补水隧道及注水孔组成的人工水幕系统作用下,建设期内地下水位下降3～5 m,地下水位距洞室顶55 m。开挖洞室附近平均垂直水力坡降大于1.0,满足设计规范及密封性要求。更多还原

【Abstract】 Aiming at analyses of surrounding rock stability of cavern group and seepage field characteristics at Dalian water-tight underground oil storage,firstly,based on regression analysis of in-situ stress testing data,initial in-situ stress field inversion is conducted with functions defined with program language Fish.Secondly,after three-dimensional random joint networks with different sizes are generated with 3DEC,a new method of calculating the anisotropy permeability is proposed.Finally,stress field and displacement field of surrounding rocks are gained using coupled fluid and mechanical excavation calculations.Based on point safety factor,whose criterion is the Mohr-Coulomb one with the tensile strength,cavern group stability is quantitatively evaluated considering parallel and vertical bedding planes owing to different materials characteristics.Referring to ideas from abroad,seepage field is analyzed by groundwater table and vertical hydraulic gradient,respectively.Results indicate that point safety factor is 1.95–2.00 for the materials in the direction perpendicular to bedding planes,while 1.02–1.25 in the direction parallel to bedding planes.With the artificial water curtain system comprised of water tunnels and holes,the groundwater drops 3–5 m during construction period,and the distance between groundwater table to cavern crown is 55 m.The average vertical hydraulic gradient is greater than 1.0 around the caverns,which meets the design specification and sealing requirement.更多还原