赞比亚下凯富峡水电站大型调压井围岩支护参数优化研究  

Study on Optimization of Surrounding Rock Support Parameters for Large Surge Shaft of Kafue Gorge Lower Hydropower Station in Zambia

作　　者：刘有全 张利平 靳俊杰 石广斌 LIU Youquan;ZHANG Liping;JIN Junjie;SHI Guangbin(PowerChina Northwest Engineering Corporation Limited,Xi'an 710065,China;PowerChina Sinohydro Bureau 11 Co.,Ltd,Zhengzhou 450001,China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,Xi'an 710048,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710065 [2]中国电建集团水电工程十一局有限公司,郑州450001 [3]陕西省岩土与地下空间工程重点实验室,西安710048

出　　处：《西北水电》2022年第6期120-126,共7页Northwest Hydropower

摘　　要：下凯富峡水电站调压井开挖深度为133.5 m,最大开挖直径为50.8 m,局部悬壁开挖深度为7.3 m,规模位于国内外同类工程前列。通过工程类比,确定围岩系统支护参数,应用三维有限元与关键块体理论计算分析不同的系统锚杆长度对围岩塑性区、变形、块体稳定的影响。结果表明:锚杆长度对围岩塑性区分布影响不明显,塑性区基本位于高程513.00 m以下,井筒和底部流道的塑性区最大深度分别为6.0 m和13.5 m,锚杆长度大于围岩塑区深度或其深度的70.0%;井壁上所有块体安全系数大于1.5,其深度基本小于锚杆入岩深度;优化后的围岩系统锚杆长度L与调压井开挖深度H之比最小值为0.033;调压井开挖过程中没有发生因支护强度不够而发生塌方,优化确定的围岩支护参数是可靠的。The excavation depth of the surge shaft of Kafue Gorge Lower Hydropower Station is 133.5 m,the maximum excavation diameter is 50.8 m,and the excavation depth of local suspended wall is 7.3 m.Based on optimization calculation and analysis,combined with the analogy of similar projects,surrounding rock support parameters are determined.Using the combined method of three-dimensional finite element and key block theory,the influence of bolt length of different surrounding rock systems on the plastic zone,deformation and block stability of surrounding rock is calculated and analyzed.The calculation results show that the length of the bolt has no obvious effect on the distribution of the plastic zone of the surrounding rock,and the plastic zone is basically located below EL513.0 m;the maximum depth of shaft and bottom channel is 6.0 m and 13.5 m respectively,and the length of anchor rod is greater than the depth of surrounding rock plastic zone or 70.0%of its depth;the safety factor of all blocks on the shaft wall is greater than 1.5,and the length of the anchor bolt is basically greater than the depth of the block.The minimum value of the ratio between the anchor length L of the optimized surrounding rock system to the excavation depth H of the surge shaft is 0.033.During the pressure regulating excavation,no collapse occurs due to insufficient support strength.Therefore,the support parameters optimized and determined in this way are reliable.

关 键 词：调压井 支护设计 参数优化 三维有限元 块体分析 

分 类 号：TV732.51[水利工程—水利水电工程]