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为防止深井沿空留巷大尺度混凝土巷旁墙体开裂破坏,通过水化热测定试验分析了充填材料的水化放热特性,在此基础上利用ANSYS软件模拟了巷旁墙体温度场的演化规律,理论计算了温度应力的变化特征,探讨了巷旁墙体在温度应力及采动应力双重作用下的破坏过程与机理.结果表明:充填前期巷旁墙体的内外温差高达22.0℃,由此引起的温度应力超过巷旁墙体的抗拉强度,致使巷旁墙体出现温度裂缝;顶板压力使温度裂缝扩展,最终导致巷旁墙体开裂破坏.基于巷旁墙体双因素致裂机理,从降低墙体内外温差及缓解顶板压力2个方面提出墙体开裂控制对策,并将其应用于1231(1)沿空留巷工程实践,取得了良好的留巷效果.
In order to prevent the cracking and destruction of large-scale concrete roadway beside gob-side entry retaining system in deep mine, the hydration and exothermic characteristics of filling material were analyzed by hydration heat test. On the basis of this, ANSYS software was used to simulate the temperature field Evolution law and the variation characteristics of temperature stress were calculated theoretically.The failure process and mechanism of roadside wall under the dual action of temperature stress and mining stress were discussed.The results show that the temperature difference between inside and outside of roadway wall before filling is as high as 22.0 ℃, The resulting temperature stress exceeds the tensile strength of the roadside wall, resulting in temperature cracks in the roadside wall; the roof pressure causes the temperature cracks to expand, eventually leading to the cracking of roadside wall body cracking.Based on the two-factor fracture Mechanism, the measures to control the cracking of the wall are put forward from two aspects: reducing the temperature difference between the inside and outside of the wall and relieving the pressure of the top wall, and applying it to the practice of 1231 (1) gob-side entry retaining project.