Dynamic Response of Heavy-Haul Railway Tunnels in Fully Weathered Coastal Red Sandstone Strata with Base Rock Reinforcement: A Numerical Study

Abstract

Xu, H.; Chen, C.; Shao, Z.; Wang, Z.; Cai, L.; Li, Z., and Xu, C., 2021. Dynamic response of heavy-haul railway tunnels in fully weathered coastal red sandstone strata with base rock reinforcement: A numerical study. Journal of Coastal Research, 37(1), 191–202. Coconut Creek (Florida), ISSN 0749-0208.Coastal fully weathered red sandstone exhibits poor cementation, and tunnels can easily develop large deformations undercrossing such rock masses under long-term cyclic loading. This article studies dynamic response of the base rock and tunnel lining structures under the dynamic load of heavy-haul train when different base rock reinforcing methods (curtain grouting reinforcement and cement-soil compaction pile reinforcement) are adopted. A tunnel undercrossing fully weathered red sandstone strata is taken as the research object, from which the rock mechanical strength parameters are obtained for a numerical model. The dynamic response of the base rock significantly decreases with the increased depth, and the inverted arch and arch foot are the most unfavorable stress locations, to which more attention should be paid. Base rock reinforcements enhance the integrity of rock mass, and the acceleration and peak stress of the rock base and lining structure significantly reduce when reinforcement is exerted. The effect of curtain grouting proved to be better, which is indicated by the reduction of acceleration and displacement of tunnel lining as well as the low value of peak acceleration and stress of the base rock.