深埋地下洞室柱状节理围岩变形特征分析  

Analysis of Deformation Characteristics of Columnar Joint Surrounding Rock of Deep Underground Cavern

作　　者：楚文杰 贾聿颉 CHU Wenjie;JIA Yujie(Zhejiang Huadong Construction Engineering Co.,Ltd.,Hangzhou 310014,China;Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,China)

机构地区：[1]浙江华东建设工程有限公司,浙江杭州310014 [2]黄河勘测规划设计研究院有限公司,河南郑州450003

出　　处：《河南科技》2023年第19期66-72,共7页Henan Science and Technology

摘　　要：【目的】金沙江白鹤滩水电站输水系统中的尾水调压室规模巨大,洞室埋深大,穹顶柱状节理玄武岩发育,地质条件复杂,为了降低围岩变形破坏的风险,保证工程安全,节约生产成本,需对深埋地下洞室柱状节理围岩变形特征进行分析。【方法】依托右岸深埋地下洞室8#尾水调压室,结合现场工程地质资料及施工过程,运用非连续介质力学的数值计算方法,得出无支护条件下穹顶在柱状节理岩体及完整岩体两种情况下围岩的应力应变分布,继而分析评价两种情况下围岩可能出现的变形特征。【结果】结果表明,柱状节理的发育使穹顶开挖面附近浅层围岩强度降低、应力集中区与开挖面的距离增大,围岩塑性区深度显著增大;受初始最大主应力方向及柱状节理各向异性影响,穹顶S侧翼围岩变形值及N/S两侧翼变形值的差异均有所增大,层间错动带C5在N侧法向应力有所减弱,在S侧的松弛变形有所增大。【结论】分析方法及结果符合地下工程设计施工的一般规律,为围岩稳定、设计方案和支护安全评价提供了有力支撑,具有可靠的工程指导价值。[Purposes]The tailrace surge chamber in the water transmission system of Baihetan Hydropower Station on Jinsha River is huge,the chamber is buried deep,the columnar jointed basalts grow in the dome,and the geological conditions is complex.In order to reduce the risk of deformation and failure of surrounding rock and ensure engineering safety,and save production costs,it is necessary to analyze the deformation characteristics of columnar joint surrounding rock of deep underground cavern.[Methods]Relying on the right bank deep buried underground caverns 8#tailrace surge chamber and combined with the site engineering geological data and construction process,the numerical calculation method of discontinuum mechanics method is used to obtain the stress-strain distribution of the surrounding rock under the condition of columnar joined-rock mass and intact rock mass under the condition of no support for 8#tailrace surge chamber,and then the deformation characteristics of the surrounding rock may occur under the two conditions are analyzed and evaluated.[Findings]The results show the strength of the shallow surrounding rock near the excavation face of the dome decreases,the distance between the stress concentration area and the excavation face increases,and the plastic zone depth of surrounding rock increases significantly due to the growth of columnar joints,in addition,both the deformation value of surrounding rock on the S side of dome and the difference of N/S two flank deformation values increase,the normal stress of interlayer dislocation zone C5 weakens on the N side and the relaxation deformation increases on the S side.[Conclusions]The analysis method and results conform to the general law of underground engineering design and construction,and provide strong support for the stability of surrounding rock,design scheme and support safety evaluation,and have reliable engineering guidance value.

关 键 词：柱状节理围岩 深埋地下洞室 尾水调压室穹顶 非连续介质 围岩变形特征 数值计算 

分 类 号：TU45[建筑科学—岩土工程]