基于灵敏度分析的下向进路参数优选及工程应用

Parameter Optimization and Engineering Application of Downward Drift Based on Sensitivity Analysis

为了有效解决下向进路两步骤回采的进路失稳问题,通过建立下向进路力学模型,分析失稳机理,建立了顶板安全系数的灵敏度响应函数,基于修正的Morris法计算出各参数的灵敏度,确定了关键影响因素及其取值范围,并将结论应用于某矿下向进路的优化实践。结果表明:下向进路各参数的灵敏度,进路宽度>假底厚度>假底抗拉强度>假底上部载荷>进路高度;关键因素及范围,进路宽度3.0~3.5 m,假底厚度0.5~0.6 m,假底抗拉强度应大于0.82 MPa。分析结果应用于矿山实践解决了进路掉渣、垮帮现象,顶板与两帮位移70 d累计量均小于10mm;基于灵敏度分析理论的下向进路参数优选具有较强的工程应用价值。

Considering the instability mechanism and failure mode of the downward drift,a sensitivity analysis model describing parameter sensitivity was established to resolve the complexity of the factors to the downward drift.The relationship between structural response function and different factors was constructed based on the sensitivity analysis model,and Morris sort method was adopted to calculate and analyze the sensitivity of the different factors,which provided the range of parameters that were given to guide parameter design of the downward drift.The results show that the sensitivity order is:drift width>thickness of false bottom>tensile strength of false bottom>load on false bottom>drift height,drift width,thickness of false bottom and tensile strength of false bottom are considered to the key factor for the stability of the downward drift,and the range of drift width is 3.0~3.5 m,the range of t thickness of false bottom is 0.5~0.6 m,the tensile strength of false bottom is more than 0.82 MPa.The key parameters of a mine were applied to engineering which were designed based on the sensitivity analysis result,practice results showed that the working slope and roof of the stope were stable with less than 10 mm’s displacement and without any dregs and collapse based on the 70 d’s monitor with SWJ-Ⅳtunnel extensometer.It is proven to be practicable in projects.