Impact of pipe-jacking construction on settlement on the expressway

Pipe jacking is a common method in trenchless construction of underground engineering. However, engineering accidents often occur when crossing some important buildings. In this paper, the project of Henkel Avenue integrated management project through the Xixian expressway (Xi 'an to Xianyang) pipe top as the research object, the numerical simulation test research. The influences of excavation progress, overburden thickness, jacking pipe diameter, formation loss rate and jacking thrust on subgrade settlement are analyzed. By comparing with the accident situation of the actual project, the results show that the settlement at the monitoring point reaches the maximum when the pipe top excavation is 10m away from the surface monitoring point. During the whole excavation process, the surface settlement at the central separation zone of the new airport expressway reaches the maximum 45mm, which is consistent with the field monitoring results. The ground settlement decreases logarithmically with the increase of overlay thickness, and increases exponentially with the increase of pipe diameter and formation loss rate. The road deformation decreases slightly with the increase of thrust.