Abstract This paper studies the influences of urban shield-driven tunneling on the stresses and displacements of adjacent bridge foundations with one, two or four piles using numerical methods. The results show that:1) the axial stress of a single-pile foundation at the side nearest the tunnel decreases while that at the side farther away from tunnel increases, and the influence decreases with an increase of horizontal distance between the pile and tunnel; 2) the axial stress of a two-pile or four-pile foundation at the side nearest the tunnel increases while that at the side farther away from the tunnel decreases; 3) the influence of tunnel construction is greater on the group-pile foundation than on the single-pile foundation, for which the stress difference between the two sides at the top of the pile farther from the tunnel increases significantly after tunnelling, and concrete on the upper part of the pile farther away from the tunnel may be subjected to tensile stress when the pile cap is close to the tunnel; 4) the vertical displacement of the piles decreases with an increase of distance between pile and tunnel, and the settlement induced by tunnelling will be relatively small when the pile bottom is located below the tunnel floor; and 5) tunnelling has the greatest impact on the horizontal displacement of the top of a pile. Specifically, the horizontal displacement decreases linearly with an increase of pile depth when the pile is far from the tunnel, while it decreases nonlinearly when the pile is close to tunnel. The displacement at the upper part of the pile decreases rapidly with an increase of pile depth, and the displacement at the lower part converges to a constant, while the displacement at the top of the pile will peak at a certain distance between the pile and tunnel.
Abstract：
This paper studies the influences of urban shield-driven tunneling on the stresses and displacements of adjacent bridge foundations with one, two or four piles using numerical methods. The results show that:1) the axial stress of a single-pile foundation at the side nearest the tunnel decreases while that at the side farther away from tunnel increases, and the influence decreases with an increase of horizontal distance between the pile and tunnel; 2) the axial stress of a two-pile or four-pile foundation at the side nearest the tunnel increases while that at the side farther away from the tunnel decreases; 3) the influence of tunnel construction is greater on the group-pile foundation than on the single-pile foundation, for which the stress difference between the two sides at the top of the pile farther from the tunnel increases significantly after tunnelling, and concrete on the upper part of the pile farther away from the tunnel may be subjected to tensile stress when the pile cap is close to the tunnel; 4) the vertical displacement of the piles decreases with an increase of distance between pile and tunnel, and the settlement induced by tunnelling will be relatively small when the pile bottom is located below the tunnel floor; and 5) tunnelling has the greatest impact on the horizontal displacement of the top of a pile. Specifically, the horizontal displacement decreases linearly with an increase of pile depth when the pile is far from the tunnel, while it decreases nonlinearly when the pile is close to tunnel. The displacement at the upper part of the pile decreases rapidly with an increase of pile depth, and the displacement at the lower part converges to a constant, while the displacement at the top of the pile will peak at a certain distance between the pile and tunnel.
ZHENG Xi-Guang-1,
HE ,
PING 1 etc
.Influence of Metro Construction on the Internal Force of Adjacent Bridge Pile Foundations[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(3): 110-118
2015, Vol. 52 