地下空区顶板破坏特征物理实验及数值模拟

针对地下空区充填后难以接顶引起顶板破坏并导致地表沉陷的问题，采用物理相似模拟和数值模拟的方法从破坏形式、应力等方面研究了地下空区顶板的破坏变形规律，并对空区顶板内部进行位移监测，降低了单一因素影响的偏离性，提高了空区顶板稳定性评价的合理性。通过物理实验发现：地下空区顶板在垂直加载下，随荷载增加，裂隙首先出现在顶板中心区域，并逐渐向侧帮发育，直至模型彻底破坏；通过数值模拟实验发现：中央区域存在拉应力集中区，该区域最容易破坏；通过监测结果发现：随载荷增加，顶板周端位移较中央部位更小，越接近顶板中心，顶板的位移量差值越小。将物理实验、数值模拟实验与监测结果进行对比，三者吻合较好。研究结果对地下空区处理、地下开采方法及矿柱的留设具有指导意义。

Physical experiment and numerical simulation of roof failure characteristics in underground mined-out area

In response to the problem that none-tight contact of filling body and the roof in the underground mined-out area causing roof damage and surface subsidence, this paper uses physical similar simulation and numerical simulation to study the damage deformation law of the roof of the underground mined-out area in terms of damage form and stress, at the same time, the internal displacement of the roof in underground mined-out area is monitored, which reduces the deviation of the influence of single factor and improves the reasonableness of the stability evaluation of the roof of the mined-out area. Through physical experiments, it is found that under vertical loading, with the increase of load, cracks first appear in the central area of the roof, and gradually develop to the sidewall, until the model is completely destroyed. Through numerical simulation experiments, it is found that there is a tensile stress concentration area in the central region, which is the most vulnerable to damage. The monitoring results show that with the increase of load, the displacement of the around roof is smaller than that of the central area, the closer to the roof centre, the smaller the displacement difference of the roof. The physical experiment, numerical simulation experiment and monitoring results are compared, and the three are in good agreement. The analysis results have guiding significance for the treatment of underground mined-out areas, underground mining methods and pillar remaining.