基于逆解法-半逆解法的煤层仰采基本顶周期来压步距计算模型研究

RESEARCH ON THE CALCULATION MODEL OF THE BASIC ROOF PERIODIC WEIGHTING STEP FOR TOPPLE MINING BASED ON INVERSE SOLUTION AND SEMI INVERSE SOLUTION

  • 摘要: 针对目前仰采工作面基本顶周期来压步距计算模型较少,根据力的合成与分解将仰采工作面基本顶周期破断受力分析模型拆分为受竖向均布荷载的悬臂梁模型和受水平均布荷载的悬臂梁模型,分别采用半逆解法和逆解法得到两种模型应力分量。然后采用叠加原理得到仰采工作面基本顶最大主应力分布形式,根据最大拉应力强度理论建立仰采工作面基本顶周期来压步距计算模型。最后采用淮北某矿Ⅲ601和涡北矿8105仰采工作面周期来压步距现场实测数据对理论模型的精确性进行验证。结果表明:基于半逆解法和逆解法建立的仰采工作面周期来压步距计算模型理论基础扎实,计算公式简便,能够同时考虑基本顶厚度、岩石抗拉强度、上覆荷载和工作面仰采角度的综合影响;理论计算得到某矿Ⅲ601和涡北矿8105仰采工作面周期来压步距分别为19.1 m和21.2 m,与现场监测的平均周期来压步距20.1 m和19.8 m基本一致,两者平均绝对误差分别仅为1.1 m和1.5 m,验证了理论计算模型的精确性;基本顶周期来压步距随基本顶厚度的增加而线性增加,随岩石抗拉强度的增加而非线性增加,随工作面仰采角度的增加而线性减小,随岩层荷载的增大而非线性减小。研究结果对仰采工作面顶板周期来压步距预测及支架选型具有重要的理论意义和工程价值。

     

    Abstract: Due to the lack of calculation models of the basic roof periodic weighting step of topple mining, according to the principle of superposition, the basic roof fracture mechanical model of the topple mining is divided into a cantilever beam model subjected to vertical load and a cantilever beam model subjected to horizontal load. The stresses of the two models are obtained using semi-inverse solution and inverse solution respectively. Then, the maximum principal stress distribution form of the basic roof is obtained using the superposition principle. Based on the theory of maximum tensile stress intensity, the basic roof periodic weighting step calculation model of the topple mining is established. Finally, the accuracy of the model is verified by using the on-site measured data of the III601 topple working face in Huaibei Mining Group and 8105 topple working face in Guobei coal mine. The results show that: The calculating model based on the semi-inverse solution and the inverse solution has a strong theoretical foundation, which can simultaneously consider the comprehensive influence of basic roof thickness, rock tensile strength, overlying load and the angle of the topple working face; The calculation results show that the periodic weighting steps of Ⅲ601 and 8105 topple working face are 19.1 m and 21.2 m, respectively, which are consistent with the average periodic weighting steps of 20.1 m and 19.8 m monitored on site. The average absolute errors of the two are only 1.1 m and 1.5 m, respectively, which verifies the accuracy of the theoretical model. The basic roof periodic weighting step increases linearly with the increase of the basic roof thickness, the nonlinearity increases with the increase of the tensile strength of the rock, the linearity decreases with the increase of the angle of the topple working face, and the nonlinearity decreases with the increase of the overlying load. The research results have important theoretical significance and engineering value for the prediction of basic roof periodic weighting step.

     

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