单井对流水溶开采盐矿采空区顶板破断机理研究

Study on Goaf Roof Fracture Mechanism of Salt Mine by Water-solution Mining with Single Well Convection

水溶开采岩盐矿床形成的采空区极易导致地表过度沉降、塌陷、土地盐碱化等地质灾害及环境安全问题,因此如何有效地预测与控制盐腔的顶板垮塌成为亟待解决的问题。首先建立了单井对流法水溶开采盐矿顶板破断分析的力学模型,然后应用弹性无孔圆板理论进行了求解,继而根据求解结果对顶板因局部张拉破损及整体失稳引起的破断机制进行了分析,最后给出了两种破断机制条件下的破坏准则。研究成果为单井水溶开采盐矿中采空区顶板破断的预测与控制提供了重要的理论依据,也为多井对流水溶开采的顶板垮断分析提供了有益参考。

The goafs formed by the solution mining in salt mine may lead to geology disasters and public environmental problems,such as excessive surface subsidence,collapses disasters and land salinization.It has been an urgent technical problem that how to forecast and control the roof fracture.Firstly,a mechanical model for goaf roof fracture in salt mine by water-solution mining with single well convection is established and solved by the theory of elastic circular plate without hole.Then,according to the solution,the mechanisms of fractures caused respectively by partial failure and integral instability are indicated.Finally,the corresponding strength criterions are summarized for above two kinds of fractures.The study is significant to forecast and control the roof fracture in single-well solution mining,and also can provide initial reference for roof fracture analysis of the multi-wells solution mining in salt mine.