Analysis for Ground Deformation Induced by Undercrossed Shield Tunnels at a Small Proximity Based on Equivalent Layer Method

Shield excavation and tail grouting are the main causes of ground deformation in tunnel construction, especially case new tunnels undercrossing existing tunnels, which have stricter requirements for settlement control. This paper investigates equivalent layer method, is used to simulate induced by shield construction via numerical analysis. The research based on a study Beijing’s newly built Metro Line 12 10, constructed soft soil. Three-dimensional finite simulation Plaxis 3D performed, incorporating method. Parametric analysis carried out explore influence thickness (?) elastic modulus (E) surface settlement. It shown that increases almost linearly with increase ?, it insensitive changes E. ? dominating factor affecting Based Beijing Lines project, predicted analyzed compared monitoring data. Metro, applicability method verified, empirical values E summarized. = 1.8 Gp 2 MPa suitable analysis, could be references other constructions With obtained caused accurately predicted, benefit reducing budget environmental protection.