Numerical investigations on dynamic responses of subway segmental tunnel lining structures under internal blasts.

Numerical simulation of segmental lining tunnel subjected to internal explosive loading is carried out in this paper based on the arbitrary-Lagrangian-Eulerian (ALE) and finite element (FE) coupled algorithms. A high-fidelity FE model considering assembled features of segmental lining structure is established, and the mapping technique is adopted to accurately simulate the explosion process. The calculated overpressure histories and failure modes of the lining structure fit well with field test results of full-scale specimens, indicating the applicability and accuracy of the numerical model. A more comprehensive numerical model considered the practical service state of segmental lining tunnel is further built based on the verified model. Influences of mechanical properties and pressure levels of surrounding soils on dynamic responses of tunnel structure under internal explosion are investigated. Numerical results show that dominated deformation modes of the segmental lining tunnel under the action of internal explosion include opening deformation at the segmental joints of the charged ring and shear deformation between the adjacent rings. The modest explosion caused by terrorist bombing attacks may severely harm the shield tunnel structure and impair its service performance, especially if the tunnel is buried in soft soil at a shallow depth • Numerical simulation of segmental lining tunnel subjected to internal explosive loading is conducted. • The accuracy of numerical simulation is verified by comparison with field test. • Mapping technique is adopted to accurately simulate the explosive load. • Dominated deformation modes of segmental lining tunnel under internal explosion are analyzed. [ABSTRACT FROM AUTHOR]