摘要
对大断面破碎围岩多次返修巷硐,锚网索支护方式难以有效控制其强流变。结合焦煤公司中马村矿39#泵房多次返修的状况,认为高应力作用下的不稳定强流变岩层,支架受力不均等因素是硐室围岩失稳的主因,提出了主动支护与被动支护联合修复方案:一次锚网索支护,二次封闭刚性支架联合支护,三次围岩注浆加固。采用蠕变数值模拟方法对原支护和返修加固方案进行了分析,结果表明:原方案在360 d时的断面收缩率达到92.2%,顶板最大下沉量达到2 792 mm,围岩处在加速蠕变失稳阶段;返修加固方案在1 000 d时的顶板最大下沉量仅56.8 mm,围岩处在蠕变稳定阶段;锚索作用在完整岩体范围内,锚杆大部分作用在塑性圈范围内,注浆范围外应力等值线密集,其峰值随时间的延长而增大,且逐渐内移。工业性试验表明:224 d时,硐室表面最大位移为18 mm,变形速率小于0.5 mm/d,修复加固取得了成功。
To large section chamber with fractured surrounding rock and repeatedly repairing, strong rheology cannot be controlled effectively with bolt-wire-cable support style. According to the repeatedly repairing 39^# pump house of Zhongmacun Colliery, Jiaozuo Coal Company, the main factors on insta-bility of surrounding rock include strong rheology strata influenced by high stress, uneven loading on steel timbers. Repair scheme combined initiative and passive support is proposed, which includes pri- mary bolt-wire mesh-cable, secondary closed steel timber and third grouting reinforcement. Original and repairing support is analyzed with creep numerical simulation. The results indicate that shrinkage percentage of chamber section is 92.2% within 360 days, and the maximum roof subsidence is 2 792 mm, and accelerated creep phase of surrounding rock appears. The maximum roof subsidence is 56.8 mm within 1 000 days, and stable creep phase of surrounding rock appears with repairing method. Ca- bles are anchored in intact rock mass, but most bolts are in plastic zone. Density of stress contour lines is very intensive outside of grouting range, whose peak value is increasing and moving gradually to deep surrounding rock with the extension of time. The field experiment shows that maximum displacement of chamber is 18 mm, and convergence ratio is less than 0.5 mrn/d after 224 days. So the repair scheme of the chamber is successful.
出处
《采矿与安全工程学报》
EI
北大核心
2013年第4期489-494,共6页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(51174078)
河南省教育厅科学技术研究重点项目(13A440334)
河南理工大学博士基金项目(B2012-077)
关键词
大断面
破碎围岩
多次返修
蠕变模拟
联合支护
large section
fracture rock mass
repeatedly repairing
creep simulation
combined sup-port
