QUAN X Z, HUANG Z Y, YAN S,et al.Numerical simulation of overburden migration in a top-coal caving face under extremely weakly cemented strata in Eastern Inner Mongolia[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(2):156-165.

doi:10.16186/j.cnki.1673-9787.2024100029

Received:2024/10/21

Revised:2025/04/25

Published:2026/01/28

Numerical simulation of overburden migration in a top-coal caving face under extremely weakly cemented strata in Eastern Inner Mongolia

Quan Xizhu1, Huang Zunying1, Yan Shuai2

1.China Resources Power （Xilingol） Coal Industry Co.， Ltd.， Xilingol  026000， Inner Mongolia， China；2.State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering， China University of Mining and Technology， Xuzhou  221116， Jiangsu， China

Abstract: Objectives To investigate the overburden migration behavior and surface subsidence characteristics induced by top-coal caving mining in the extremely weakly cemented Cretaceous strata of Eastern Inner Mongolia， a numerical simulation study was carried out using a typical working face of the Wujianfang coalfield as the engineering background. Methods A particle flow numerical model was first established based on PFC2D 5.0， and the rationality of model parameters was verified by comparing the simulated surface subsidence with in-situ measured data. The overburden migration characteristics were then analyzed by integrating force chain diagrams， principal stress distributions， and displacement fields. Finally， a sensitivity analysis was conducted to evaluate the effects of burial depth， mining height， and advancing speed on overburden migration.  Results The results indicate that the overlying strata generally experience three stages： formation and rapid dissipation of a caving arch， gradual formation of a subsidence basin， and periodic expansion of the subsidence basin. The peak range of the front abutment pressure is 8.19~11.86 MPa， and the maximum deviatoric stress reaches 10.76 MPa at a mining distance of 200 m. Although the overall stress level is relatively low， it is significantly higher than the mechanical strength of the rock strata. The maximum surface subsidence values at the end of the three stages are 0.95 m， 6.67 m， and 8.85 m， respectively， which are notably larger than those observed in western Jurassic coal mines. Sensitivity analysis shows that the R-values of mining height， burial depth， and advancing speed are 5.37， 2.76， and 2.01， respectively， indicating that mining height has the greatest influence on overburden migration.  Conclusions The findings provide theoretical guidance for the prevention and control of mining-induced hazards in extremely weakly cemented Cretaceous strata in Eastern Inner Mongolia.

Key words: Cretaceous; extremely weakly cemented strata; particle flow code; overburden migration; sensitivity analysis