GAO B B, CHEN Z B, REN L W, et al.Study on ‘activation’ and critical load of the foundation in the  mined-out area under a high-speed railway[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(1):70-76.

doi:10.16186/j.cnki.1673-9787.2023090030

Received:2023/09/14

Revised:2024/03/08

Published:2025-12-03

Study on ‘activation’ and critical load of the foundation in the  mined-out area under a high-speed railway

Gao Baobin1,2, Chen Zhibin1,2, Ren Lianwei3, Zou Youfeng4, Wang Xin1,2, Zhu Hongbo1,2, Ren Chuangnan1,2

1.State Key Laboratory Cultivation Base for Gas Geology and Gas Control， Jiaozuo  454000， Henan， China；2.School of Safety Science and Engineering， Henan Polytechnic University， Jiaozuo  454000， Henan， China；3.School of Civil Engineering， Henan Polytechnic University， Jiaozuo  454000， Henan， China；4.School of Surveying and Land Information Engineering， Henan Polytechnic University， Jiaozuo  454000， Henan， China

Abstract: Objectives This study aims to reasonably predict the threshold at which the dynamic load of high-speed trains may cause ‘activation’ of the foundation in mined-out areas. Methods A combination of theoretical analysis and numerical simulation was employed to systematically investigate the determination of foundation ‘activation’ in mined-out areas beneath high-speed railways， the dynamic loads imposed by trains， and the corresponding calculations of train speed and axle load. Based on the ‘activation’ criteria and dynamic load analysis， a method for calculating the critical load of high-speed railway foundations above mined-out areas was established and applied to engineering practice to obtain the critical load， corresponding critical static axle load， and critical train speed. Numerical simulations using MIDAS software were conducted to determine the height of water-conducting fractured zones and the range of critical loads， thereby verifying the feasibility and accuracy of the proposed method and theoretical calculations. Results The results indicate that when a high-speed train passes over a mined-out area， the critical load is 26.60 t. For a designed static axle load is 17 t， the corresponding critical speed is 188.24 km/h； for a designed speed of 250 km/h， the critical static axle load is 15.20 t. When the train operates below the critical load of 26.60 t， the foundation in the mined-out area is unlikely to be ‘activated’. However， if the train simultaneously runs at the design speed of 250 km/h and a static axle load of 17 t， the load reaches 29.75 t， exceeding the calculated critical load. In this case， treatment of the mined-out area is necessary to ensure the safety of both the railway and the train. Conclusions The findings provide valuable guidance for the construction and treatment schemes of high-speed railway foundations above mined-out areas.

Key words:high-speed railway;mined-out area;goaf ‘activation’;traffic loadnumerical simulation