高应力硬岩板裂化破坏现象普遍存在于工程地质和采矿工程现场,而以此诱发的板裂屈曲岩爆也给深部资源的安全高效开采带来了严峻挑战。为了分析深部高应力硬岩板裂屈曲岩爆的力学机理与控制对策,对板裂化岩体建立了正交各向异性薄板力学模型,推导出双向受力条件下板裂屈曲岩爆临界荷载值;在解出弯曲形变势能的基础之上,依据能量法求得了薄板压曲状态下的挠度值。提出采用充填法的控制对策以防治板裂屈曲岩爆的发生,并推导出充填体所需的围压值。研究结果表明:①针对竖向层状岩体中发生的板裂屈曲岩爆现象,应对板裂化岩体建立正交各向异性薄板力学模型进行相关力学机理的研究;②轴向应力的增加不仅促进了板裂化破坏的形成,还加剧了板裂屈曲岩爆发生的可能性;③在一定范围内,板裂体在压曲作用下的水平挠度值随板厚的减小而增大,且当长高比为4√E2/E1时,有最大挠度值;④在对采空区进行充填时,较小的充填体围压值便可以有效抑制板裂屈曲岩爆的发生。
Brittle slabbing failure of deep highly-stressed hard rocks exists in engineering geology and mining engineering extensively, and the slab buckling rockburst induced by slabbing failure also brings severe challenge to safe and high-efficient excavation of deep resources. In order to analyze the mechanism and control strategy of slab buckling rockbursts of high-stressed hard rocks, a mechanical model for orthotropic thin plate is established for slabbing rockmass, and the critical load of slab buckling rockburst under two-dimensional stress condition is also deduced. The deflection value under buckling is calculated according to the energy method on the basis of acquiring the bending deformation potential energy. The filling method, deemed as the control strategy, is proposed to prevent slab buckling rockbusts, and the rational confining pressure is deduced accordingly. The research results indicate that (1) For those phenomena of slab buckling rockbursts which occur in vertical layered rock mass, it is necessary to establish a mechanical model for orthotropic thin plate for slabbing rockmass when proceeding the relevant mechanical analysis; (2) The increase of axial stress promotes the formation of slabbing and intensifies the possibility of slab buckling rockbursts; (3) The horizontal deflection value, within a certain range, may increase with the decrease of plate thickness under buckling, and has the maximum value when the length-to-height ratio of thin plate is equal to 4√E2/E1 ; (4) A relatively low confining pressure value can prevent the occurrence of slab buckling rockbursts when adopting the filling method in deep engineering.