Refined model analysis of basement rock degradation mechanism of heavy-haul railway tunnel

Abstract

This study investigated the degradation mechanism of the surrounding rock of a heavy-haul railway under a water-rich condition, based on the construction of the Taihangshan tunnel for the Wari Railway, a heavy-haul railway that used standard construction practices for axle loads of 30 t. Remote monitoring demonstrated that the coupling effect between the dynamic load of a heavy-haul train and the groundwater leads to the deterioration and hollowing of the surrounding rock. This study clarified the void evolution process and deterioration mechanism of the basement rock under the comprehensive influence of the groundwater–train dynamic load using a refined discrete element numerical simulation. The results revealed that the groundwater was the primary influencing factor in the deterioration of the lower part of the heavy-haul railway tunnel. Rock particles were gradually lost under the effects of long-term erosion due to groundwater and heavy-haul trains, which inevitably damaged the basement rock after the construction was completed. Based on this observation, the critical conditions for the deterioration and attenuation law of the physical parameters of the basement rock were obtained. The results of this study can provide ideas and serve as a reference for the forecasting and disaster treatment of basement rock damage in heavy-haul railway tunnels.

Keywords

• Heavy-haul railway tunnel
• Refined model analysis
• Degradation mechanism
• Surrounding rock
• Water-rich condition