LAUSR

Abstract When new metro tunnels undercrossing existing tunnels, deformation is inevitably caused in the stratum and the existing structures. However, the calculation results by conventional prediction methods often bring large errors compared to measured or simulated data because the complex influences of the stiffness of existing structures is always neglected. According to the equivalent layered method, an existing tunnel can be considered as an equivalent rock stratum instead. Based on the Peck formula, a theoretical model for predicting the deformations caused by construction of a new tunnel undercrossing an existing tunnel is established. This paper mainly picks the Metro Line 10 undercrossing the Metro Line 1 of Beijing subway as an engineering case study. The comparison shows that results by the prediction model fits the measured data well. The proposed model are widely applicable and provides a new prediction method to study the deformations of existing tunnels and strata caused by the undercrossing new constructions.