ABSTRACT
During the construction period of the shield tunnel, the stratigraphic conditions, tunnel burial depth, and driving parameters will all have a specific impact on the segment floating. If the segment floating is too large, it may cause a safety problem for the shield tunnel. Relying on the tunnel project of Nanchang Metro Line 4 (Anfeng Station~Dongxin Station), we summarize and analyze the monitoring values of the segment floating when the shield passes through different strata using the mathematical statistics method. Then, the shield tunnel construction model is established by ABAQUS software, to study the influence of varying tunnel burial depths and main driving parameters on segment floating. Research results show that: (1) The amount of the segment floating is closely related to the stratigraphic conditions. When the shield machine is driving in different strata, the value of the segment floating will also change. (2) The greater the tunnel buried depth, the smaller the amount of the segment floating. When the buried depth changes from 15 m to 21 m, the amount of the segment floating basically shows a significant linear relationship with the buried depth. (3) With the increase of the three main driving parameters, the amount of the segment floating shows a linear increasing trend, and the influence of grouting pressure and mud silo pressure on segment floating is stronger than that caused by the total shield thrust.
