考虑充填顺序与后壁黏结力的采场充填计算统一解

以统一强度理论的平面应变抗剪强度公式为基础,合理考虑中间主应力效应、充填顺序、后壁黏结力和顶部超载等综合影响,推导大深宽比采场充填计算时充填料的所需黏聚力统一解和充填体的安全系数统一解,并结合工程算例给出简化公式以及示范计算,继而分析其可比性,最后探讨各因素的影响特性。研究结果表明:本文统一解涵盖了众多的已有解答与新准则解答,具有广泛的理论意义和很好的可比性;2种不同用途的充填计算公式都十分简单,便于实际工程选择及使用;中间主应力效应、充填顺序和后壁黏结力对采场充填计算的影响均很显著,指出现有文献的结果偏于保守,对这3种因素的有效利用可产生重要的经济效益;顶部超载的影响亦不容忽视,应慎重估计顶部超载以实现充填优化计算。

A unified solution for calculating mine backfills considering the backfilling order and the back wall cohesion

On the basis of the shear strength formulation arising from unified strength theory under plane strain conditions,unified solutions of the required cohesion and the safety factor of the backfill were derived for mine backfills with a high height-to-width ratio. Influencing factors such as the intermediate principal stress effect,the backfilling order and the back wall cohesion as well as the top surcharge were comprehensively considered in the unified solution. The solutions were simplified combining with an engineering case and applied to a specific example. Comparability analysis of the proposed solution was conducted, and parametric studies were also carried out. It was found that the proposed solution contains many conventional and new results and hence, has extensively theoretical value and good comparability. It was also shown that calculation formulas of mine backfills for two different objectives are both easy to use and choose in engineering practice. The influence of the intermediate principal stress effect,the backfilling order and the back wall cohesion on the calculation of mine backfills is significant,and effective usages of these three factors can generate an important economic benefit. Existing results available in the literature are conservative in comparison to the proposed result. The influence of the top surcharge cannot be neglected and should be evaluated for obtaining an optimal calculation of mine backfills.