深井大型硐室厚坚硬底板破坏机理及控制技术

Damage and control mechanism of thick and hard floor of large chamber in deep mines

针对深井大型硐室厚坚硬底板底鼓难题,以千米深井唐口煤矿绞车房硐室为工程实例,研究底板破坏机理:深井大型硐室厚坚硬底板开挖初期表现出明显的分层屈曲损伤破坏特征,随后在高应力作用下沿损伤破坏面滑移错动鼓起;以薄板屈服理论推导了底板屈曲破坏临界载荷。以控制厚坚硬底板的屈曲损伤破坏为出发点,基于硐室底板整体加固控制原则,提出了底板组合桩基群加固治理技术:以反底拱技术为基础,借助底板横向组合钢梁及双层链接钢筋网,辅以混凝土整体浇筑组合形成底板强基础梁结构,均衡底板受力,防止局部地点高应力集中;以高预应力锚索束和高压封闭注浆技术胶结加固围岩形成底板组合桩结构,阻断围岩应力向底板传递和转移;最终形成多排锚索束张拉强基础梁的组合桩基群结构,现场应用效果良好。研究成果对于当下日益加深的深部大型硐室及大型地下空间支护具有一定的指导和借鉴意义。

Aiming at the floor heave problem of thick and hard floor of large chamber in deep mines thewinch room in Tangkou Mine about akilometer in depth is taken as an engineering case, and the damage mechanism of thick and hard floor is studied. In earlyexcavation, the floor sustains obvious layered damage bybuckling and then slidesandmoves along damage fracture surface under the action of high ground stress. The critical load for damage bybuckling is derived based onbuckling theory of thin plate. Forcontrolling the damage bybuckling of floor, based on the principle of strength and control of the whole floor, the technology of composite piles and foundation of thickandhard floor in large chamber is proposed as follows： based on inverted arch and combined transverse steel beams andchained double reinforcingmeshes,concrete is poured to form strong foundation beam so as to balance the force and preventstress concentration of floor. The combined anchor wires and high-pressure grouting are used to form composite piles to block the floor stress to transfer from the surrounding rock and to balance the stress. Finally composite piles and foundation are formed, and the efficiency ofengineering application is satisfactory.The research may be helpful to controlling large chambers in deep mines and largeunderground spaces.