基于岩体流变性的矿井防突岩柱临界安全厚度计算方法

矿井巷道在穿越含瓦斯断层或揭煤掘进过程中常常遇到前方岩柱保护厚度与延期突出问题。为了探索岩柱防突厚 度与时间的非线性耦合关系，应用RLW-2000型岩石三轴流变仪，对含煤岩系中的砂质泥岩、砂岩和泥岩进行了分级加载条件下的单轴压缩蠕变试验。通过对经典流变组合模型的分析及Matlab最小二乘迭代法的拟合，建立了改进的的七元件非线性黏弹塑性本构模型，并建立了基于岩体流变性的岩柱临界安全厚度的计算模型。豫西大平煤矿实例计算表明，埋深612 m的泥岩巷道，防突岩柱使用年限在10、20、30 a时相应的保护厚度分别为8.73、23.56、39.41 m；理论安全岩柱厚度与该矿“10 ? 20”瓦斯突出案例较为吻合，计算模型对同类工程具有一定的借鉴意义。

A method for caculating critical safe thickness of rock pillar for prevention of gas bursting based on rock rheological properties

In the course of driving through the gas fault or cutting through the coal seam, it often encounters the problems that the thickness of rock pillar protection and delay outburst issues in mine roadway. In order to explore the nonlinear coupling relationship between thickness of rock pillar protection and time, compression creep test of sandy mudstone, sandstone and mudstone are conducted by using triaxial rock creep apparatus RLW-2000 under step loading in this article. By analyzing the combination of classical rheological models and Matlab least squares iteration, an improved seven elements nonlinear constitutive model of viscoelastic plasticity is established as well as the calculation model based on the pillar of rock rheology critical safety thickness. The results of case study of Daping Mine in Western Henan show that when the life spans of anti-burst pillar of mud roadway in the depth of 612 m are 10, 20, 30 years, the corresponding protection thicknesses are 8.73, 23.56, 39.41 m. The theoretical safety rock pillar thickness is consistent with outburst case of Oct. 20th; the calculation model has certain reference significance for similar engineering.