Numerical study on damage morphology of shallow overburden reinforced concrete tunnel with pre-ground improvement

抄録

Pre-ground improvement is an auxiliary method for shallow overburden tunnels in which the tunnel excavation is performed after improving the ground on top of the tunnel with/without sides by the replacement method and/or the cement mixing method. Although it has been confirmed in previous studies that pre-ground improvement enhances the tunnel face stability and reduces the settlement of the ground surface during the tunnel excavation, the seismic behavior of tunnels with pre-ground improvement has not been fully investigated. In this study, a two-dimensional elasto-plastic finite element analysis is performed on an actual reinforced concrete shallow overburden tunnel with a ground improvement. The damage of the reinforced concrete tunnel during earthquakes is discussed in detail.