Abstract:  With the development of China’s highspeed railway construction, more and more highspeed railway projects are aligned over areas with unfavorable geological conditions, such as, abandoned mining caverns. The stability of the railroad over mining caverns becomes increasingly more important and need to be addressed. This paper presents a case history of the ground subsidence and cavern collapse evaluation for a railway tunnel near the abandoned mining caverns in Zhang Jihuai Highspeed Railway Project. Based on the analogy analysis, the ground subsidence area of an abandoned Du Ye manganese ore mining caverns and its influence zone as well as the tunnel deformation are numerically simulated by the FLAC 3D finite element software. The results indicate that, the deformations of the abandoned mining caverns were concentrated in the upper crown area and area along the bedrock dip direction; areas outside the deformation concentration has little deflections. The influence distance for the abandoned mining cavern on the railway tunnel is conservatively taken as 221 meters and the deformation of the tunnel induced by the mining caverns are within the allowable limits.

Key words: abandoned mining caverns, railway tunnels, analogy analysis, numerical simulations, deformation influence area