摘要
深部超大断面硐室群因初始地应力高、断面尺寸大、硐室间距小等原因,控制难度很大。本文采用相似材料试验方法,以龙固煤矿井下煤矸分离系统硐室群为背景,设置3条超大断面硐室,利用数字散斑测试系统、声发射监测技术、应力监测系统等进行综合监测,得到深部超大断面硐室群围岩变形破裂演化规律。结果表明:单一超大断面硐室开挖后围岩整体变形较小且呈对称分布,裂隙发育较少;相邻硐室开挖导致围岩变形呈非对称性,裂隙发育明显增多。上部硐室开挖后其围岩变形以底鼓和两帮收敛为主,下部硐室围岩应力集中和变形均有较大幅度减小,即对下部围岩应力集中起卸载作用,有条件时硐室群应优选"品"字形布置以有利于维护。硐室群开挖前后锚杆受力变化与围岩应力、变形近似呈正相关关系,不同部位受力差别较大,应根据硐室群不同部位特点针对性设计支护参数。本研究揭示了深部超大断面硐室群围岩破裂演化规律,可为其围岩控制设计提供参考。
Because of the high initial in-situ stress, large cross-section size and small space between chambers, it is very difficult to control the deep super-large section chamber group. In this paper, similar material test method has been used to set up three super-large section chambers with chamber group of coal gangue separation system in Longgu Coal Mine as engineering background. The evolution law of surrounding rock deformation and fracture in the deep super-large section chamber group has been included through comprehensive monitor of digital speckle test system, acoustic emission monitoring technology and stress monitoring system. The result have shown that after the single super-large section chamber has been excavated, the overall deformation of surrounding rock is small and symmetrical, and the cracks developed less, while the excavation of adjacent chambers results in the asymmetric deformation of surrounding rock and the obvious increasing of cracks. After the excavation of the upper chamber, the deformation of surrounding rock is dominated by floor heave and convergence of both sides. The stress concentration and deformation of surrounding rock of the lower chambers greatly reduced, i.e., it unloads the stress concentration of surrounding rock of the lower chambers. When conditions permit, the triangle-shaped layout should be selected to facilitate the maintenance of the chamber group. The stress variation of bolt before and after excavation is approximately in positive correlation with the stress and deformation of surrounding rock, and the force bearing in different parts are quite different. Therefore, the supporting parameters should be designed according to the characteristics of different parts of the chamber group. The evolution of surrounding rock fracture of deep super-large section chamber group is revealed in this study, which can provide reference for its surrounding rock control design.
作者
刘学生
宋世琳
范德源
范文昌
宁建国
王洪磊
LIU Xuesheng;SONG Shilin;FAN Deyuan;FAN Wenchang;NING Jianguo;WANG Honglei(State Key Laboratory of Mining Disaster Prevention and Control Cofbunded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;College of Mining and Safety Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Shandong Xinjulong Energy Co Ltd,Heze,Shandong 274918,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2020年第1期40-49,共10页
Journal of Mining & Safety Engineering
基金
国家重点研发计划项目(2018YFC0604703)
国家自然科学基金项目(51804181,51874190)
山东省重点研发计划项目(2019GSF111020)。
关键词
超大断面
硐室群
变形破裂
数字散斑
声发射
super-large section
chamber group
failure evolution
digital speckle
acoustic emission
