中国西部弱胶结地层覆岩组合结构对采动裂隙发育的影响及其高度预测

Influence of overburden combination structures on mining‑induced fracture development and its height prediction for weakly consolidated formation in Western 

Abstract: Underground space excavation, particu larly in mining operations, significantly compromises the integrity of overlying rock-soil structures and ground infrastructure, resulting in issues. This study discusses how different overburden combination structures affect the development of mining-induced fractures and further predicts the height of the frac tures in weakly consolidated formations in Western China. Using the matrix discrete element method, we an alyzed the evolution and height development of water-conducting fractured zones (WCFZs) under three composite structures, including upper soft lower hard (USLH), upper hard-lower soft (UHLS), and soft-hard interbedded (SHI) strata. Besides, field measured data collected from weakly consolidated strata in Western China are applied to develop an empirical formula for predicting the failure height of the weakly cemented formations. The research results show that: (1) the mining-induced fractures develop more rapidly in hard rock than soft rock, and the steady fracture height varies significantly across dif ferent composite structures. (2) Based on the an alysisof vertical stress, break heat distribution, and ele ment connection, the mining-induced fracture height is highest in the UHLS strata (~ 130 m), followed by the SHI strata (~ 105 m) and then the USLH strata (~ 91 m), respectively. (3) The proposed formula, val idated by measured data, demonstrates high predic tion accuracy (94.89%), so the mathematical model can be well applied to predicting WCFZs in weakly cemented strata. This study provides new insights into the law of overburden failure and the height of mining-induced fractures during mining, especially the coal mines with the weakly cemented strata.

Keywords: Overburden combination structures；Mining-induced fractures；MatDEM；Weakly consolidated formation；Empirical formula

Fig.1 Schematic diagram of different combinations overburden migration characteristics

Fig.2 Comparison of measured value and predicted value

Fig.3 Geological data source for numerical simu lation

Fig.4  Schematic diagram of linear elastic model: a Packed model; b Normal spring force; c Tangential spring force (Liu 2019)

Fig.11 Correlation an aly sis result of five factors

Li W, Zhu J, Li D, et al. Influence of overburden combination structures on mining-induced fracture development and its height prediction for weakly consolidated formation in Western China[J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2026.