a supershallow buried large-span rectangular pipe jacking tunnel undercrossing an expressway: construction method, monitoring results, and numerical simulation

In this study, the rectangular pipe-jacking tunnel project of the liuye avenue west extension under the changzhang highway is used to study highway pavement settlement and deformation during pipe-jacking construction through on-site monitoring. a three-dimensional numerical simulation method is employed to analyse the factors contributing to the significant settlement and rebound of the pavement. this study identifies the fundamental law governing the development of pavement settlement over time. the findings indicate that settlement increases rapidly when the jacking distance reaches approximately 10 m and then stabilizes at a consistent growth level. furthermore, completion of the jacking of the left pipe leads to a transition in the surface settlement groove from a v-type distribution to a w-type distribution. comparative analysis reveals that horizontal and vertical displacements exhibit similar characteristics, with maximum displacements occurring in the lagging jacking area. on both sides of the axis, the settlement groove curve remains stable within a range of 30–40 m, while the horizontal displacement curve stabilizes within a range of 20–30 m. © the author(s), under exclusive licence to the iran university of science and technology 2023.