某地下大型洞室群开挖变形特性及参数敏感性分析  

Excavation deformation characteristics and parameter sensitivity analysis of a large underground cavern group

作　　者：杜林学 王文[2] 史向荣[3] DU Linxue;WANG Wen;SHI Xiangrong(Jinan Pioneer Investment Group Co.,Ltd.,Jinan 250000,China;Department of Architecture and Civil Engineering,Shandong Urban Construction Vocational College,Jinan 250103,China;College of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]济南先行投资集团有限责任公司,山东济南250000 [2]山东城市建设职业学院建筑工程系,山东济南250103 [3]山东建筑大学土木工程学院,山东济南250101

出　　处：《山东建筑大学学报》2024年第4期89-96,共8页Journal of Shandong Jianzhu University

摘　　要：地下工程施工顺序的选择和支护措施的实施,直接关系到洞室群的整体稳定性和安全性。文章以某水电站大型地下洞室群开挖为例,通过建立三维数值模型,研究了主厂房、主变室和尾水调压室3种不同的开挖顺序下洞室群开挖后洞周围岩的变形特性,分析了参数的敏感性,并给出了洞室群开挖支护设计。结果表明:方案2(并行与顺序开挖相结合)在控制位移和塑性区面积方面表现更优,建议施工时优先选择;侧压力系数是影响洞室稳定性的关键因素,侧压力系数较小时,边墙为重点支护部位,而侧压力系数较大时,顶拱位移就较大;围岩破碎面的黏聚力、内摩擦角和抗拉强度对围岩的稳定性具有决定性的影响。洞室的主厂房顶拱采用锚喷支护和注浆的方法控制围岩的位移量,其余部位采用锚杆和锚索共同支护的方式,支护后锚固使洞室的主厂房顶拱、上、下游边墙的位移值减小幅度为10%~25%,而塑性区的面积也减小了40%~50%。The selection of construction sequences and implementation of support measures for underground engineering are crucial for ensuring overall stability and safety of the tunnel group.Taking large-scale underground caverns(main powerhouse,main transformer and tailrace surge chamber)of hydropower station for example,a three-dimensional numerical model is established.Then the stability of the underground caverns in accordance with the three excavation schemes are analyzed and the deformation characteristics of the surrounding rock masses after excavation of the cavern are obtained.The sensitivity of parameters is analyzed,and the excavation support design of the cavern group is given.The results show that scheme 2,which combines parallel and sequential excavation,offers superior control of displacement and plastic zone area,making it the preferred choice.The lateral pressure coefficient emerges as a critical factor affecting cavern stability.Lower cofficients focused support on the sidewalls,whereas higher coefficients increase the top arch is large displacement.The cohesion,internal friction angle and tensile strength of the broken surface of surrounding rock diversely impact its stability.The displacement of the surrounding rock is controlled by the method of bolting and shotcrete support and grouting,and the displacement of the surrounding rock is controlled by the method of bolting and shotcrete support and grouting.Furthermore,the other parts are supported by the method of bolting and anchor cable.After the support,the displacement value of the roof arch,the upper and lower side walls of the main powerhouse of the cavern is reduced by 10%~25%,and the area of the plastic zone is also reduced by 40%~50%.

关 键 词：地下洞室群 围岩稳定性 数值模拟 开挖顺序 敏感性分析 

分 类 号：TV731[水利工程—水利水电工程] TU923[建筑科学—建筑设计及理论]