煤矿充填开采连续曲形梁形成与岩层控制理论
Continuous curved beam formation and strata control theory in coal backfill mining
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摘要: 在充填开采大量工程实践和物理相似试验基础上,提出了充填开采上覆岩层连续曲形梁理论模型,当密实充填率达到一定条件时,顶板不会产生断裂,仅发生弯曲变形,形成连续的曲形梁,能有效地控制关键层的沉降变形。阐述了连续曲形梁的几何特征和力学特征,指出了顶板形成连续曲形梁的条件。通过建立力学模型,计算得出了连续曲形梁变形的理论解和便于工程应用的工程解,进一步分析得到连续曲形梁与关键层的量化关系,为密实充填率的设计提供了理论依据。此外,对连续曲形梁的三维模型及其理论解和数值解做了一些有益的分析和探索,揭示了充填开采对岩层变形的控制机理。Abstract: Based on a large number of engineering practice and physical similarity experiments,a theoretical model of continuous curved shape beam has been proposed to describe the mechanical behavior of overlying strata in backfill mining. Before the filling rate reaches a critical value,the roof will not fracture. And there are only bending deforma- tion and no penetrating cracks in overlying strata. These conditions result in forming a continuous bending shape beam structure at overlying strata. The structure can prevent the subsidence deformation of key rock stratum. In this paper, the geometric features and mechanical characteristics of the continuous curved beam are proposed. And the continuity conditions of the continuous curved beam are also provided. Through establishing the mechanical model,the authors have obtained the theoretical solution and simple engineering solution of the continuous curved beam deformation. The quantitative relationship between the continuous curved beam and the key layer is also analyzed,which can provide a theoretical basis for the filling rate design. A 3D model of continuous curved beam is discussed in detail. And its theo- retical solution and numerical solution are also obtained. The control mechanism of rock deformation is revealed for backfill mining.