Prediction of ground settlement on shielded water-rich sand layer considering groundwater level and tunnel depth

Abstract

In order to research the effect of different groundwater level and tunnel depth on the ground settlement law for the shield construction of the water-rich sand layer, monitoring data of Fuzhou Metro Line 6 project is adopted and analyzed. The finite element software Plaxis 3D is used to carry out the numerical simulation of the project. Using the “activate” and “deactivate” functions of Plaxis 3D finite element software, the jack thrust, grouting pressure, face pressure, shield machine advancement and splicing of the segment are simulated. The calculation results in terms of vertical displacement of ground surface are in good agreement with the actual monitoring data. Using this numerical simulation method, under the combined action of different groundwater level and different tunnel depth, the ground settlement law of shield in the water-rich sand layer is studied, and the following conclusions are drawn: the shallower the groundwater level in the same tunnel burial depth The greater the surface settlement, the greater the buried depth of the tunnel and the smaller the surface settlement.