Research on the Shield Tunneling Construction Passing Through the Maglev Pile Foundations in Saturated Soft Soil Strata

Abstract

Shield tunneling projects in the central city of the soft soil area usually have limited conditions of auxiliary reinforcement protection measures. In this paper, the influence of the shield tunneling construction on the nearby maglev pile foundations, which is carried out by means of the non-reinforcement protection measures, is studied by numerical analysis and field measurement method. By setting the field test section and the simulation section, this paper puts forward the construction plan and the key parameters of the shield tunneling construction to meet the requirements of the maglev operation and deformation control. The influence of the shield tunneling on the deformation of the maglev bridge pier and the track is analyzed. The results of the research and engineering implementation show that the pressure setting of the shield tunnel is the key parameter to control the settlement of the bearing cap. For the pressure-type pile foundation, the undervoltage range of the shield tunneling pressure is 0.01–0.02 MPa to maintain the pile foundation cracking and the external balance, which can be determined according to the test section with a multi-stage method proposed in this paper; the filling rate of the synchronous grouting is 150%–180%, for filling the formation loss to ensure that the surface subsidence within the allowable range.