面向耕地保护的充填体-煤柱协同承载及地表沉陷控制研究

Research on collaborative bearing of filling body and coal pillar and control of surface subsidence for farmland protection

耕地是粮食安全的基石,而煤炭则是能源供应的保障。然而,采煤引起的耕地损毁问题在我国高潜水位平原煤粮复合区尤为显著。为了应对这一问题,提出基于充填体-煤柱协同承载体的区域性沉陷控制方法,以实现采煤效益与耕地保护之间的平衡。以河南省某矿区为例,基于面向耕地保护的区域性沉陷控制方法,首先,分析了充填体-煤柱协同承载体的形成过程及其设计原则;随后,使用PFC软件模拟了不同充实率对充填体-煤柱协同承载体稳定性的影响,并基于FLAC3D软件模拟确定了满足耕地保护指标的最优工作面开采参数。研究结果显示:充填体会对煤柱产生侧向支撑,有利于提高煤柱稳定性,形成共同支撑覆岩的协同承载体。当充实率达到85%时,充填区裂纹约占总数的73.42%,此时充填体在协同承载体中发挥主要承载作用,系统处于稳定状态。进一步分析表明,采空区位于应力释放区,而协同承载体位于应力集中区,其应力集中系数呈现出随采宽增大而上升的趋势。在综合考虑充填成本和耕地保护指标后,确定了该矿区最佳的区域性沉陷控制开采参数为采宽160 m、充填宽100 m。该参数设置既能够节约充填成本,又能有效控制地表下沉量,达到耕地保护的标准。该研究成果可为煤粮复合区的绿色开采提供理论依据和工程参考。

Farmland is the cornerstone of food security,while coal is essential for energy supply.However,the problem of farmland damage caused by coal mining is particularly significant in highwater-table plain areas where coal and grain production overlap in China.To address this issue,firstly,a regional subsidence control method based on the collaborative bearing of the filling body and coal pillar is proposed,aiming to balance coal mining efficiency with farmland protection.Using a mining area in Henan Province as a case study,the process of forming the collaborative bearing system of the filling body and coal pillar and its design principles are first analyzed.Subsequently,the effects of different filling rates on the stability of this system are simulated using PFC software.FLAC3D software is then used to determine the optimal mining parameters that meet farmland protection requirements.The results indicate that the filling body provides lateral support to the coal pillar,enhancing its stability and forming a collaborative bearing system that supports the overlying strata.When the filling rate reaches 85%,cracks in the filling area account for approximately 73.42% of the total,with the filling body playing a major bearing role in the system,which is stable at this rate.Further analysis reveals that the goaf is located in the stress relief zone,while the collaborative bearing system is in the stress concentration zone,with the stress concentration coefficient increasing as the mining width expands.Considering both filling costs and farmland protection indicators,the optimal regional subsidence control mining parameters for this mining area are determined to be a mining width of 160 meters and a filling width of 100 meters.These parameters not only reduce filling costs but also effectively control surface subsidence,meeting farmland protection standards.The results of this study provide theoretical support and engineering references for green mining in coal and grain production areas.