Abstract In order to study the pile foundation responses during the excavation and operation periods of tunnels in soft clay soils, this paper uses the finite difference software FLAC3D to carry out a 3D fine numerical simulation of the step-by-step excavation of a shield tunnel under the CVISC model and derives the pile foundation responses varying with tunnel excavation progress and rheological time, and it comprehensively analyzes the spatial and temporal effects of the pile foundation responses induced by adjacent shield tunnel excavation and the shielding effects of the pile group under considering the rheological properties of soils. The results show that the impact of tunnel excavation on the pile foundation is mainly concentrated between one time the tunnel diameter in front of the pile foundation and 2.5 times the tunnel diameter behind the pile foundation; after the tunnel excavation is completed, the internal force and displacement of the pile foundation will continue to increase for a long time before it becomes stable,and the axial force of the pile foundation will be the first to become stable while the settlement will take the longest time to reach stability; The shielding coefficient of the internal force in the pile group is larger than that of the displacement, which will gradually increase with the increase of the rheological time.
Abstract：
In order to study the pile foundation responses during the excavation and operation periods of tunnels in soft clay soils, this paper uses the finite difference software FLAC3D to carry out a 3D fine numerical simulation of the step-by-step excavation of a shield tunnel under the CVISC model and derives the pile foundation responses varying with tunnel excavation progress and rheological time, and it comprehensively analyzes the spatial and temporal effects of the pile foundation responses induced by adjacent shield tunnel excavation and the shielding effects of the pile group under considering the rheological properties of soils. The results show that the impact of tunnel excavation on the pile foundation is mainly concentrated between one time the tunnel diameter in front of the pile foundation and 2.5 times the tunnel diameter behind the pile foundation; after the tunnel excavation is completed, the internal force and displacement of the pile foundation will continue to increase for a long time before it becomes stable,and the axial force of the pile foundation will be the first to become stable while the settlement will take the longest time to reach stability; The shielding coefficient of the internal force in the pile group is larger than that of the displacement, which will gradually increase with the increase of the rheological time.
YAN Haojie ZHENG Junjie PAN Yu CHEN Pengfei
.Time-Space Effect of Pile Foundation Responses Induced by Adjacent Shield Tunnel Excavation[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(4): 133-140
2021, Vol. 58 