摘要
煤矿底部高地应力软岩巷道在开挖、支护后会表现出的连续底臌、顶沉、肩缩等非线性大变形现象,这些现象具有明显流变性质。结合工程实际研究高应力软岩巷道变形及成套耦合支护技术。结果表明:1产生非线性变形破坏的关键部位在煤矿底部高应力倾斜岩层巷道断面与岩层倾斜方向成钝角的部位;2围岩塑性区的大面积扩展直接导致巷道两肩收敛变形严重;3底部高强地应力与构造应力叠加,导致无支护的底板岩土体发生塑性流动,形成连续性底臌变形,诱发岩巷两肩剧烈收敛。以锚网支护为基础,提出成套耦合支护控制方法,施以补强锚索、二次加密高强锚杆、持续渐进让压托盘、设置底角锚杆、加护底板注浆锚杆、使用可缩性U形钢支架等支护方法控制巷道非线性变形。通过数值模拟分析成套耦合支护技术的支护效果,对比现场监测结果,验证支护实际功效。
The large nonlinear rheological deformation of highly stressed soft-rock roadways of coal mining due to the excavation and support includes floor heaves, roof subsidence, sides shrinkage etc. The deformation mechanism of highly stressed soft rock roadways and their combined support technique is studied based on the engineering cases. Main conclusions include （1） The nonlinear deformation failure mostly occurs at the locations where the roadway section and the inclined rock bedding intersect with an obtuse angle. （2） Extensively developed plastic zones in surrounding rock directly lead to severe sides inward deformations. （3） The superposition of the strong ground stress and the tectonic stress can cause the rheological deformation of unsupported bottom rocks, resulting in the continuous floor heaves of bottom rocks and then severe sides inward deformation. Based on the anchor-net method a set of combined support techniques is used to control the deformation, including the reinforcement anchorage cables, the supplemented high-strength and spaced rock bolts, the anti-sliding floor anchorage piles, the grouted bolts and flexible U-shaped steel support, contrast with the field monitoring results, the numerical simulation performed indicates that the combined closely etc. In support technique as developed is an effective supporting approach.
出处
《土木工程学报》
EI
CSCD
北大核心
2015年第8期96-101,共6页
China Civil Engineering Journal
基金
国家自然科学基金(51304235
51104094)
关键词
极破碎围岩
成套耦合支护
数值分析
高应力软岩
poorly fractured surrounding rock
combined support technique
numerical simulation
highly-stressed soft rock
