摘要
以兴安矿四水平18层南轨道巷为背景,针对高应力条件下软弱底板挠曲型底鼓支护难题,研究了挠曲型底板围岩的破坏特征,提出了钢管混凝土底板桩基支护形式。首先基于板的挠度理论和虚功原理,建立了底板桩基支护条件下挠曲型底板的失稳判据,研究了底板桩基的支护机理。然后通过数值分析方法,研究了设计参数对支护效果的影响及支护后的底板应力分布规律。结果表明,底板围岩的高应力和围岩强度不足是引发巷道底板失稳的主要原因,改善底板围岩应力环境和强化底板围岩是挠曲型底鼓治理的关键;底板桩基的几何参数和桩间距是决定极限阻隔抗力的关键因素,桩长宜采用0.4 R~0.6 R(R为塑性区半径)嵌固深度,底板桩基钻孔方向应与巷道截面等效圆半径一致或偏向垂直位移方向。根据底板桩基现场应用试验结果,底板桩基对巷道底板围岩的挤压应力有较好的阻隔效果,可较好地控制底板及两帮变形,提高巷道稳定性。该技术可以为类似条件下的巷道底鼓支护提供参考。
In order to solve the problem of flexural floor heave support under the condition of weak floor with high stress,the supporting form of concrete filled steel tube floor corner pile is put forward.The failure characteristics of the surrounding rock of the flexural floor are studied on the research background of the 18-floor south track roadway of the fourth level in Xing’an Mine.Based on the deflection theory of slab and the virtual work principle,the instability criterion of flexure-type floor under the condition of floor corner pile support is given,and the support mechanism of foundation pile is studied. The results show that the high stress and insufficient strength of surrounding rock are the main rea-sons for the instability of roadway floor and weakening the stress of floor rock and strengthening the floor rock are the key to control the flexural floor heave. The sectional geometry parameters and pile spacing of piles are the key design parameters to determine the ultimate resistance. The pile length should in-clude the embedding depth of 0. 4 R ~ 0. 6 R(R is the plastic zone radius),and the pile should be laid through the equivalent circle radius of the roadway section or in a vertical direction. Based on the above research,a field test was carried out on floor corner pile. The field monitoring results show that the pile foundation stress of the floor has a good barrier effect on the compressive stress of the surrounding rock of the roadway floor,and the deformation of the floor and the two sides can be well controlled,and the stability of roadway can be significantly improved. This control technology can provide a reference for roadway floor heave support under similar conditions.
作者
郭东明
亢鑫超
陆志颖
陈麒宇
张伟
赵志峰
曹延鹏
Guo Dongming;Kang Xinchao;Lu Zhiying;Chen Qiyu;Zhang Wei;Zhao Zhifeng;Cao Yanpeng(School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Jiangsu Haosen Architecture Design Co.,Ltd,Changzhou Jiangsu 213022,China)
出处
《矿业科学学报》
CSCD
2021年第5期536-547,共12页
Journal of Mining Science and Technology
基金
国家自然科学基金(51974315)。
关键词
挠曲型底鼓
底板桩基
支护机理
应力阻隔
底鼓控制
flexural floor heave
floor corner pile
support mechanism
stress resistance
floor heave control
