极软地层巷道围岩变形机理与控制技术研究
Study on deformation mechanism and control technology of roadway surrounding rock in ultra soft strata
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摘要: 为了解决北皂煤矿海域二采区回风巷围岩强度低、自承能力差、变形速度快、难以维护的难题,从围岩力学特性、软岩巷道流变特性、扰动影响、巷道底鼓、围岩失水风干崩解等方面进行了研究。研究结果表明:在揭示该类巷道围岩变形机制基础上,提出了高强度钢管混凝土支架支护方案,巷道断面采用圆形,钢管混凝土支架支护钢管选用Φ194 mm×8 mm钢管,接头套管选用Φ219 mm×8 mm的钢管,充填标号C40混凝土,支架壁后辅助钢筋网支护和混凝土喷碹支护,监测出支架的变形量为20~80 mm,最大变形也只达到80 mm,支架没有明显变形,钢管混凝土支架支护方案能够控制北皂煤矿海域二采区回风巷围岩变形,保持巷道围岩的稳定。Abstract: In order to solve the low strength, poor bearing capacity, quick deformation and hard maintenance difficulty of the surrounding rock in the second mining block under the sea area of Beizao Mine, from the surrounding rock mechanics features, rheological features of the soft rock mine roadway, study was conducted on the disturbance influences, floor heave, dewatering and drying disintegration of the surrounding rock and other aspects. The deformation mechanism of the surrounding roc k in the type roadway was revealed. A support plan with high strength steel tube concrete supports was provided. The cross section of the mine roadway was circular. T he support steel tube of the steel tube concrete supports would be a中194 mmx8 mm steel tube and the joint coupling of the steel tube would be a中219 mmx8 mm ste el tube. The backfill would be conducted with C40 concrete. Behind the support wall, the auxiliary steel bar mesh support and shotcrete support would be made. The sit e test results showed that the deformation value of the support was 20 ~ 80 mm, the max deformation was 80 mm only, the support had not obvious deformation, the su pport plan with the steel tube concrete support could be able to control the surrounding rock deformation of the air return gateway in No. 2 mining block under the seam area of Beizao Mine and the surrounding rock of the gateway was kept in stable.