Cite this article as:

Chuan Fan, Li Li, Guangsheng Liu, Xiaocong Yang, Weidong Song, Lijie Guo, and Ruofan Wang, Numerical analysis of the stability and minimum required strength of sill mats considering creep behavior of rock mass, Int. J. Miner. Metall. Mater., (2025). https://doi.org/10.1007/s12613-024-3029-y
Chuan Fan, Li Li, Guangsheng Liu, Xiaocong Yang, Weidong Song, Lijie Guo, and Ruofan Wang, Numerical analysis of the stability and minimum required strength of sill mats considering creep behavior of rock mass, Int. J. Miner. Metall. Mater., (2025). https://doi.org/10.1007/s12613-024-3029-y
引用本文 PDF XML SpringerLink

围岩蠕变作用下充填体顶板稳定性及强度需求数值模拟研究

摘要: 下向充填采矿法广泛应用于地下金属矿山高应力或破碎矿体开采。该方法通常是在采场顶部构筑的胶结充填体顶板下作业,合理评估充填体顶板最低强度需求是保障作业人员设备安全并优化胶凝材料消耗量的关键。目前仅少量文献报道了充填体顶板强度需求的确定方法,而现有方法均忽略了围岩蠕变效应产生的收敛变形及其对充填体顶板稳定性和强度需求的影响。本文采用数值模拟方法,首次探究了围岩蠕变效应对充填体顶板最低强度需求的影响规律。结果表明,经典Mitchell法主要适用于无围岩收敛变形影响的充填体顶板强度需求评估;围岩蠕变作用下充填体顶板强度需求随开采深度的增加而增加;忽略围岩蠕变效应将显著低估顶板强度需求并导致下向揭露稳定性风险;当开采深度较大且围岩蠕变变形显著时,设计采用低刚度且合理匹配强度的充填体顶板,有利于降低顶板的压剪破坏概率;及时充填采空区以减少充填体顶板下向暴露时间,有助于改善充填体顶板稳定性并降低其强度需求。

 

Numerical analysis of the stability and minimum required strength of sill mats considering creep behavior of rock mass

Abstract: The underhand cut-and-fill mining method is widely employed in underground mines, especially when the quality of surrounding rock mass or ore body is inferior or subjected to high stresses. Such a method typically requires the construction of sill mats with cemented backfill to provide operators with safe artificial roofs. Accurate estimation of the minimum required strength of the sill mat is crucial to minimize binder consumption and ensure its stability upon base exposure. Over the years, only a few publications were devoted to determining the minimum required cohesion (cmin) of sill mats. None of them considered rock wall closure to be associated with the creep of surrounding rock mass. Moreover, the effect of rock wall closure associated with rock creep on the cmin of the sill mat remains unknown. Thus, a series of numerical simulations was performed to fill this gap. The influence of rock creep on the cmin of base-exposed sill mat was investigated for the first time. The numerical results indicate that Mitchell’s models could be suitable for sill mats subjected to negligible wall closure. However, this scenario is rare, especially when mine depth is large. In general, the cmin of sill mats increases as mine depth increases. Neglecting rock creep would significantly underestimate the cmin of sill mats. When mine depth is large and the rock mass exhibits severe creep, cemented backfill with ductile behavior (i.e., with low stiffness but enough strength) should be considered to reduce binder consumption and prevent crushing failure. In all cases, promptly filling the mined-out stope below the sill mat can improve its stability and reduce its cmin value.

 

/

返回文章
返回