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为研究长壁留煤柱采空区系统荷载传递规律,采用改进矩阵力法并结合数值模拟对煤柱群-顶板结构荷载传递规律进行研究。以某煤矿长壁留煤柱开采为例,采用改进力法,即支反力F取代等效弯矩Xn,建立了煤柱群-顶板力学模型;结合数值模拟研究局部煤柱承载力衰减对临近煤柱承载力影响规律,以及煤柱群-顶板整体系统塑性区域扩展和应力分布规律。结果表明:1)随局部煤柱承载力衰减,荷载逐渐转移到周围煤柱之上,临近煤柱分担荷载最多,相隔煤柱受到的影响较小;2)若相邻煤柱因转移荷载而压溃,则荷载将进一步向外转移扩散,影响煤柱顶板系统整体稳定性;3)荷载转移率是影响煤柱群-顶板结构稳定性的重要因素,当各个煤柱承载力较为均衡时,荷载转移率较高,与力法分析结果相近。当转移荷载过大时,顶板围岩也参与到分担转移荷载的工作中,顶板围岩系统稳定性影响非常大,很可能在未导致临近煤柱失稳时,该处局部顶板已经发生了垮落,对整体稳定性产生威胁,这不但与荷载转移率有关,也与顶板围岩性质密切相关,也是继局部煤柱失稳后威胁煤柱群-顶板整体系统稳定的原因所在。
In order to study the law of system load transfer in the gob of longwall coal pillar, the law of load transfer of coal pillar group-roof structure was studied with improved matrix force method and numerical simulation. Taking the long pillar coal pillar mining in a coal mine as an example, the improved force method, that is, the supportive force F instead of the equivalent bending moment Xn, is established to establish the mechanical model of coal pillar group - roof. The numerical simulation is used to study the attenuation of partial coal pillar load capacity Near the coal pillar bearing capacity impact law, as well as the coal pillar group - roof plastic system of the overall expansion and stress distribution. The results show that: 1) With the decreasing of the bearing capacity of partial coal pillar, the load is gradually transferred to the surrounding coal pillar, with the most adjacent load being adjacent to the coal pillar and less affected by the coal pillar; 2) Crushing, then the load will be further transferred to the outside diffusion, affecting the overall stability of the coal pillar roof system; 3) load transfer rate is an important factor affecting the stability of coal pillar group - roof structure, when the bearing capacity of each coal pillar is more balanced, Load transfer rate higher, similar to the force analysis. When the transfer load is too large, the surrounding rock of the roof is also involved in the work of sharing the transfer load. The stability of the surrounding rock system of the roof is very greatly affected. It is likely that the local roof of the roof has been collapsed Which is not only related to the load transfer rate but also closely related to the nature of roof rock. It is also the reason why the overall coal pillar group-roof system is threatened after the failure of local coal pillar.