Horizontal response of existing pile induced by adjacent shield tunnelling with large longitudinal slope

Abstract

The horizontal displacement and bending moment of piles due to adjacent shield tunnelling with a large longitudinal slope were investigated. An analytical calculation method for the horizontal response of shield tunnelling to piles was presented, considering the included angle, the tunnel-soil-pile interaction, and the shielding effect of the pile group. A new formula for soil horizontal deformation was derived by combining the cutterhead thrust force, the frictional force between the shield and soil, the grouting pressure and the soil loss, and the pile response was calculated as it was subjected to the generated ground displacement. The reliability of the analytical method was verified by the existing analytical solution, field monitoring data, and numerical simulation results. A parametric analysis of the longitudinal slope angle, shield tunnelling parameters, and soil modulus was conducted to assess their influences on tunnelling-induced pile deflection and bending moment. Finding that the increase in the longitudinal horizontal response of the pile is more prominent before the shield arrives at its side and the instant peak values of the horizontal response of the pile increase with increasing longitudinal slope angle. As the shield arrives at the pile side, the increase in the longitudinal horizontal response of the pile reaches the maximum value, and the influence of changes in the longitudinal slope angle on the horizontal response of the pile is not significant. The transverse horizontal response of the pile changes more after the shield passes through it and shows an increasing trend, the peak value of the transverse horizontal response of the pile is nearly 1 time that of the shield arriving at its side with passing through it of 20 rings. The changing trend of the horizontal response of the pile with increasing longitudinal slope angle after the shield passes the pile is opposite to that before arriving at its side. The cutterhead thrust force and the shield shell friction force are suggested to be positively correlated with the grouting pressure to reduce pile deformation. The horizontal response of piles caused by the shield tunnelling load decreases with increasing longitudinal slope angle after the shield passes through. The horizontal response of the pile is more significantly affected by the change in the longitudinal slope angle of shield tunnelling in the stratum with a smaller soil elastic modulus.