A Finite Element Analysis of Tunnel Lining Demolition by Blasting for Subway Tunnel Expansion

In this paper, a practical project of subway tunnel lining demolition via blasting for the construction station under action load and weight collapsed rock mass was proposed. The overbreak underbreak quality, failure mechanism structure, particle peak velocity (PPV), stress evolution law surrounding caused by were researched using LS-DYNA. Firstly, results show that parameters presented in paper can maintain cross-section smooth outline excavation or quality control. Secondly, tensile existing exceeded concrete strength, radius burst fracture 0.86 m, which is greater than thickness (0.7 m). Thirdly, peaked within 0.1 × 10−3 s after blasting, occurred. Moreover, relationship between PPV distance from center shows used effectively control PPV. Therefore, study reveals expansion tunnels into stations method improve efficiency construction.