摘要
针对深废矿坑高陡边坡极限承载力问题,综合考虑锚索锚固岩体的压力墙和组合梁作用,结合Hoek-Brown强度准则,采用特征线法推导得到了矿坑高陡边坡极限承载力计算方法。结合工程实例,就坡度α、岩石力学参数GSI、m_(0)以及锚索的主动支护力等影响因素对矿坑岩壁岩石地基极限承载力的影响进行了分析,研究表明:(1)承载力系数随坡度的增加呈线性降低,当GSI为45、m_(0)为7时,也即矿坑岩壁岩体为质量较差的石灰岩时,加锚后其承载力约为加锚前承载力的1.32~1.54倍,考虑锚索的组合梁作用可作为安全储备;(2)随着岩体质量越来越好,地基极限承载力系数增长的幅度越来越大,当坡度α为60°、GSI取85,坑壁为好岩体时,承载力系数值为1.28;GSI取45,坑壁为较差岩体时,承载力系数值为0.23;前者约为后者的6倍,表明岩体质量指标的好坏对承载力的影响较大。
Aiming at the ultimate bearing capacity of high and steep slope in deep waste pit, the calculation method of ultimate bearing capacity of high and steep slope in mine pit is deduced by using characteristic line method in combination with Hoek-Brown strength criterion and considering the action of pressure wall and composite beam anchored by anchor cable. In combination with engineering examples, the influence of slope α, rock mechanics parameters GSI, m_(0) and active support force of anchor cable on ultimate bearing capacity of rock foundation of mine wall is analyzed. The research shows that:(1) The bearing capacity coefficient decreases linearly with the increase of slope. When the GSI is 45 and m_(0) is 7, that is, when the rock mass of the pit wall is of poor quality limestone, the bearing capacity after anchoring is about 1.32-1.54 times of the bearing capacity before anchoring. Considering the combined beam action of anchor cable, it can be used as a safety reserve;(2) With the quality of rock mass getting better, the ultimate bearing capacity coefficient of foundation increases more and more greatly. When slope α is 60° and GSI is 85, bearing capacity coefficient is 1.28 when pit wall is good rock mass;when GSI is 45 and pit wall is poor rock mass, bearing capacity coefficient is 0.23;the former is about 6 times of the latter, indicating that the quality index of rock mass has a great influence on bearing capacity.
作者
何昌杰
雷勇
邓加政
李建新
陈秋南
He Changjie;Lei Yong;Deng Jiazheng;Li Jianxin;Chen Qiunan(China Construction Fifth Engineering Bureau Co.,Ltd.,Changsha 410004,P.R.China;Key Laboratory of Geotechnical Engineering Stability Control and Health Monitoring,Hunan University of Science and Technology、Xiangtan,Hunan 411201,P.R.China;Third Engineering Company,China Construction Fifth Engineering Bureau,Changsha 410004,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2022年第2期635-641,共7页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51878270)。
关键词
矿坑高陡边坡
极限承载力
特征线法
锚索
high and steep slope of pit
ultimate bearing capacity
characteristic method
anchorage cable
