基于应变软化模型的煤柱采动应力分布精细化数值模拟

    Fine numerical simulation of mining stress distribution in coal pillar based on strain softening model

    • 摘要: 本文以山西经坊煤业3-边角08工作面工程地质条件为背景,开展了工作面护巷煤柱采动应力的现场钻孔应力实测;分别建立了基于摩尔-库伦(MC)本构模型以及应变软化(SS)本构模型的数值计算模型,精细研究了综放工作面煤柱采动应力空间分布及演化规律。现场钻孔应力监测及数值模拟结果表明:与传统的MC模型相比,基于SS模型的精细化数值模拟能够准确地获得综放工作面煤柱采动应力空时分布规律,其结果更接近于现场钻孔应力监测结果;基于SS模型的煤柱上的支承压力峰值位置滞后工作面40~50 m,而基于MC模型煤柱采动应力峰值位置始终处于采空区中部,不能反映采空区顶板垮落破断对采动应力分布规律的影响;基于SS模型的煤柱上的侧向支承压力和工作面前方的超前支承压力分别相比基于MC模型的结果分别小43.3%和26.2%。研究成果对于指导综放工作面护巷煤柱尺寸留设以及巷道布置与支护设计具有一定的理论与工程指导意义。

       

      Abstract: Based on the engineering geological conditions of 3-corner 08 working face of Shanxi Jingfang coal industry, the in-situ borehole stress measurement of mining stress of coal pillar protecting roadway in working face is carried out.On this basis, the numerical calculation models based on the Moore Coulomb (MC) constitutive model and the strain softening (SS) constitutive model are established respectively, and the spatial distribution and evolution law of mining stress on coal pillars in fully mechanized caving face are studied in detail.The results of in-situ borehole stress monitoring and numerical simulation show that compared with the traditional MC model, the refined numerical simulation based on the SS model can accurately obtain the spatial distribution of mining stress of coal pillar in fully mechanized caving face, and the results are closer to the in-situ borehole stress monitoring results.The peak position of the abutment pressure on the coal pillar based on the SS model is 40-50 m behind the working face, while the peak position of the mining stress on the coal pillar based on the MC model is always in the middle of the goaf, which cannot reflect the influence of the caving and breaking of the goaf roof on the distribution law of the mining stress.The lateral abutment pressure on the coal pillar and the advance abutment pressure in front of the working face based on the SS model are 43.3% and 26.2% smaller than those based on the MC model, respectively.The research results have certain theoretical and engineering significance for guiding the size of coal pillar and roadway layout and support design in fully mechanized caving face.

       

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