摘要
为了分析自然崩落法在覆岩整体性较好的构造应力型矿山应用的可行性,以龙桥铁矿为工程背景,借助数值计算、现场监测手段,重点对顶板岩层移动冒落力学响应机理进行研究。结果表明:构造应力促使离空区一定距离的顶板覆岩形成明显的应力集中区,并随空区跨度增大沿顶板覆岩向地表方位移动,同时伴有应力集中和应力释放的现象,构造应力成为破坏顶板覆岩完整性的动力源,增加顶板覆岩自然冒落的机率;空区的形成,使得空区相邻顶板覆岩为拉应力区,且随空区跨度增大沿倾向和纵向方位扩展,拉应力值呈平稳增加趋势,当跨度趋近临界跨度时,顶板覆岩拉应力值增大明显,预示着空区顶板呈现移动冒落现象;空区跨度继续增大时,覆岩拉应力值在保持平稳波动外,顶板覆岩遭受拉伸剪切破坏的范围在扩大,顶板岩层也在持续冒落。
In order to analyze application of natural caving method in tectonic stress type mines with good strata integ- rity, taking Longqiao iron mine as engineering background, response mechanism on movement and caving of roof rock was emphatically studied by numerical calculation and site monitoring. The results showed that the tectonic stress made the roof rock, having a certain distance from the goaf, form a significant stress concentration area. As the goaf span in- creased, the stress concentration area moved to the surface along the roof rock with stress concentration and stress re- lease. Tectonic stress became the power source to damage the integrity of roof rock and increased the probability of nat- ural caving for roof rock. The goaf made the adjacent roof rock as a tensile stress zone which expanded along inclination and lengthways as the goaf span increased, and the tensile stress value presented a steady increasing trend. When the span was close to the critical span, tensile stress values of the roof rock increased obviously, which indicated that the goaf roof presented movement and caving. When the goal span continued to increase, besides the stable waves of ten- sile stress, the scope of roof rock suffered from tensile and shear failure was expanded, and the roof rock was caving constantly.
出处
《矿业研究与开发》
CAS
北大核心
2015年第7期58-62,共5页
Mining Research and Development
基金
国家自然科学基金项目(51004007
51064009)
江西省自然科学基金项目(2010gqc0067)
关键词
构造应力
自然崩落法
顶板覆岩
移动冒落
响应特征
Tectonic stress, Natural caving method, Roofrock, Movement and caving, Response characteristic
