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Simplified Solution for Tunnelling-Induced Pile Foundation Deformation Based on the Kerr Foundation Model
(1 Key Laboratory of Geohazard Prevention of Hilly Mountains, Ministry of Land and Resources, Fuzhou 350002; 2 School of
Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093; 3 State Key Laboratory of Building Safety and Environment, China Academy of Building Research, Beijing 100013; 4 State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059)
Abstract The elastic subgrade reaction method based on the Winkler foundation model is widely used in the anal?
ysis of laterally loaded piles. However, the shearing action in the foundation soil mass is neglected in this model. For this reason, the free-field soil mass displacements induced by tunnelling were calculated using the cylinder cavity contraction theory, which is more accurate than the Loganathan & Poulos (1998) solution. Then, based on the Kerr foundation model, which fully considers the shearing behaviors of the soil mass, the free-field soil displacement was applied to the pile foundation and a simplified solution for pile foundation deformation under the disturbance of passive displacements was established. The calculated results of the soil mass free-field displacements and pile deformations were compared with existing calculated results, 3D FEM numerical simulation results and measured data,and consistency was achieved with the cylinder cavity contraction theory proven to be more accurate. Finally, relative parameters of the Kerr foundation model, pile diameters, ground loss ratio and spacing of the pile and tunnel were analyzed. The results show that the thickness of the shear layer and pile diameter are inversely proportion to the pile′s lateral displacement; the ground spring parameter, ground loss ratio and spacing between the pile and tun?
nel are proportional to the lateral displacement of the pile foundation; and when the thickness of the shear layer is zero, the foundation model degenerates into a Winkler foundation model, while the foundation spring parameters set as infinity means the foundation model degenerates into a Pasternak foundation model
Abstract：
The elastic subgrade reaction method based on the Winkler foundation model is widely used in the anal?
ysis of laterally loaded piles. However, the shearing action in the foundation soil mass is neglected in this model. For this reason, the free-field soil mass displacements induced by tunnelling were calculated using the cylinder cavity contraction theory, which is more accurate than the Loganathan & Poulos (1998) solution. Then, based on the Kerr foundation model, which fully considers the shearing behaviors of the soil mass, the free-field soil displacement was applied to the pile foundation and a simplified solution for pile foundation deformation under the disturbance of passive displacements was established. The calculated results of the soil mass free-field displacements and pile deformations were compared with existing calculated results, 3D FEM numerical simulation results and measured data,and consistency was achieved with the cylinder cavity contraction theory proven to be more accurate. Finally, relative parameters of the Kerr foundation model, pile diameters, ground loss ratio and spacing of the pile and tunnel were analyzed. The results show that the thickness of the shear layer and pile diameter are inversely proportion to the pile′s lateral displacement; the ground spring parameter, ground loss ratio and spacing between the pile and tun?
nel are proportional to the lateral displacement of the pile foundation; and when the thickness of the shear layer is zero, the foundation model degenerates into a Winkler foundation model, while the foundation spring parameters set as infinity means the foundation model degenerates into a Pasternak foundation model
ZHANG Zhi-Guo- 1,
2 ,
3 etc
.Simplified Solution for Tunnelling-Induced Pile Foundation Deformation Based on the Kerr Foundation Model[J] MODERN TUNNELLING TECHNOLOGY, 2016,V53(6): 55-66
2016, Vol. 53 