摘要
为了研究深部开采覆岩变形破坏规律,基于深部岩体的脆延转化特性,采用解析分析方法,对深部采场上覆岩层极限承载能力进行了研究。结果表明:深部岩体在拉应力超过弹性极限强度后表现出塑性软化特性,承载能力随拉应变的增大而降低;深部开采上覆岩层的变形破坏规律主要受弯矩支配;随着采煤工作面的推进,采空区长度逐渐增大,上覆岩层所受弯矩逐渐增加,拉应变逐渐增大,当局部拉应力达到弹性极限强度时岩层处于弹性极限状态;随着采煤工作面的继续推进,弯矩继续增加,拉应变继续增大,最终岩层达到塑性极限状态,弯矩达到塑性极限值,岩层失去承载能力而断裂。关键岩层达到塑性极限状态时,因断裂而释放大量变形能,诱发冲击地压等矿山动力灾害。
In order to understand the deformation laws of overlying rock in deep mining,this study investigates the ultimate bearing capacity of overlying rock in deep mining based on the brittle-to-ductility transformation characteristic of deep rock mass and using analytical method.The results show that the bearing capacity of deep rock mass is decreasing with the increase of tensile strain because the deep rock mass has plastic soften characteristic after the tensile stress exceeds the elastic strength limit.The overlying strata deformation and failure laws are mainly affected by bending moment in deep mining.With the advance of longwall face,the length of goaf zone increases gradually,and also bending moment and tensile strain increase.The rock strata are in the elastic limit state when local tensile stress reaches the elastic strength limit.The bending moment and tensile strain will continue to increase with the advance of longwall face.This will result in that rock and bending moment reaches a plastic limit value,and then the rock stratum will break due to the bearing capacity is exceeded.A large amount of deformation energy will be released when the key rock stratum reaches the plastic limit state,and it can easily induce dynamics disaster.
出处
《辽宁工程技术大学学报（自然科学版）》
CAS
北大核心
2010年第6期1013-1015,共3页
Journal of Liaoning Technical University (Natural Science)
基金
国家重点基础研究发展计划基金项目资助(2010CB226803)
关键词
深部开采
上覆岩层
脆延转化
极限弯矩
deep mining
overlying rock
brittle-to-ductility transformation
ultimate moment
