“砌体梁”结构关键块体回转速度影响支架阻力机理研究

The scientific and accurate determination of the capacity of support is one of the most important but unsolved problems in the research field of ground pressure. The fundamental reason is that it is difficult to quantitatively evaluate the load transferred to supports during the breakage and movement of key strata in different layers above the support in stopes. Research shows that the load transmission between adjacent layers of voussoir beam structures in overburden is closely related to the rotational speed of key blocks, and ultimately affects the load bearing state of the supports in working face. The research aims to reveal the internal relationship between the rotational speed of key blocks and load transmission, which is important to quantify the support’s load. This project synthesizes the elastic-plastic mechanics, rock mechanics and theoretical mechanics to establish the mechanical model of rotational speed of key blocks of voussoir beam structure, obtain the equation of rotational speed of key blocks, clarify the mathematical relationship between rotational speed of key blocks of adjacent voussoir beam structure and its load transmission, and thereby master the top-down transmission mechanism of overlying load in the process of rotational movement of key blocks of multi-layers voussoir beam structure above stope. Based on this, the coupling relationship between the rotational speed of key blocks of the lowest voussoir beam structure under the influence of overlying strata and the support resistance will be revealed, and a method for determining the support capacity based on the rotational speed of key blocks of the lowest voussoir beam structure is proposed. The research will provide an important theoretical reference for support’s selection and design and roof control in stopes.

科学准确地确定支架工作阻力是矿压研究领域尚未解决的重要问题之一，其根本原因在于难以定量表征采场上覆不同层位关键层破断运动传递给支架的载荷。研究表明，相邻两层“砌体梁”结构间的载荷传递与其关键块体回转速度密切相关，并最终影响支架的受载状态。因此，深入研究并揭示关键块体回转速度与载荷传递的内在联系，对准确确定支架载荷至关重要。本项目综合弹塑性力学、岩石力学及理论力学，建立“砌体梁”结构关键块体回转速度力学模型，解析关键块体回转速度方程，据此揭示相邻“砌体梁”结构关键块体回转速度与其载荷传递量的数理关系，并掌握采场上覆多层“砌体梁”结构关键块体回转运动时覆岩载荷自上而下的传递机制，从而建立上覆岩层载荷影响下最下位“砌体梁”结构关键块体回转速度与支架阻力的耦合关系，最终提出基于最下位“砌体梁”结构关键块体回转速度的支架阻力确定方法。项目研究将为支架选型设计及采场顶板控制提供重要理论依据。

覆岩关键层破断块体相互铰接形成“砌体梁”结构，“砌体梁”结构对工作面矿压显现的影响主要表现为两个方面。一方面为“砌体梁”结构铰接块体回转运动结束后，结构终态稳定性对采场矿压显现的影响，即传统矿压控制中的砌体梁结构的“S-R”稳定理论；另一方面表现为覆岩最下位关键层“砌体梁”结构铰接块体回转运动速度大小对矿压显现的影响。深入研究砌体梁结构铰接块体回转运动速度对支架受力及矿压显现的影响规律，掌握顶板岩层破断块体全期运动过程回转规律及其与工作面支架的互馈耦合响应特征，剖析来压持续期间不同阶段顶板岩层运动与支架的相互作用关系对基于顶板岩层破断块体运动特征来确定支架阻力，实现支架阻力的精细化确定具有重要意义。项目综合弹塑性力学、理论力学以及岩层力学，构建了涵盖上覆岩层载荷大小、铰接块体自重载荷、铰接块体上位关键层砌体梁结构下向传递的附加载荷、后方铰接块体挤压作用推力以及工作面支架阻力的砌体梁结构铰接块体回转速度力学模型，解析获得了铰接块体在上述主要参量影响下的回转速度方程表达式。同时借助于“子弹穿木块”经典力学模型，基于能量守恒及动量定理，研究了覆岩多层“砌体梁”结构铰接块体回转运动过程中块体载荷传递准则，以载荷层厚度量化了附加载荷，揭示了关键层载荷与附加载荷叠加效应下砌体梁结构铰接块体回转运动影响影响支架阻力机制，阐明了铰接块体回转运动速度对支架增阻率、支架活柱下缩量、持续来压长度等矿压显现强度评价指标的影响规律。在此基础上，进一步通过判断覆岩不同层位关键层砌体梁结构铰接块体回转运动速度相对大小关系，揭示了采场上覆多层“砌体梁”结构关键块体回转运动时覆岩载荷自上而下的传递机制，阐明了高位关键层砌体梁结构回转运动影响下位砌体梁结构运动特征及支架阻力机制，确定了影响采场支架受力的覆岩关键层临界高度。项目研究成果将为大采高及特大采高综采、综放工作面的支架选型设计及采场顶板控制提供重要理论参考。