A Prediction Model for the Potential Plastic Zone Induced by Tunnel Excavation Adjacent to a Pile Foundation in a Gravity Field

The construction of metro tunnels in urban areas often encounters existing underground structures, such as the pile foundations of adjacent existing buildings. Under the mutual effects and impacts of pile foundation load and tunnel excavation, the soil around tunnel and pile foundations can experience stress redistribution or even yield prior to support installation, which could adversely affect and even damage the adjacent pile foundations. This paper proposes an effective prediction model consisted of axisymmetric tunnel and pile foundation to investigate the shape and range of potential plastic zones induced by tunnel excavation adjacent to pile foundations. Then the results obtained from the proposed method are compared with the existing approaches and numerical simulations, which shows that the shape of the potential plastic zone develops towards a butterfly shape in a gravity field, similar to those from numerical simulations. Finally, a parametric analysis is performed to investigate the influences of different parameters, such as soil parameters, axisymmetric boundary conditions, and pile parameters on the boundaries of the potential plastic zone. This proposed prediction model might provide a certain basis for making protective measures for existing pile foundations influenced by tunnel excavation, and provide a quick estimate of the boundaries of the potential plastic zone induced by tunnel excavation adjacent to pile foundations in a gravity field, thus resulting in time and cost savings.

[1]  Richard A. Regueiro,et al.  Pile and pile group response to tunnelling using a large diameter slurry shield – Case study in Shanghai , 2014 .

[2]  K. Park ELASTIC SOLUTION FOR TUNNELING-INDUCED GROUND MOVEMENTS IN CLAYS , 2004 .

[3]  Kaihang Han,et al.  Explicit Form of Exact Analytical Solution for Calculating Ground Displacement and Stress Induced by Shallow Tunneling and Its Application , 2019, Advances in Civil Engineering.

[4]  Andrew J. Whittle,et al.  Ground Movements due to Shallow Tunnels in Soft Ground. I: Analytical Solutions , 2014 .

[5]  Alec M. Marshall,et al.  An analytical study of tunnel–pile interaction , 2015 .

[6]  Yong-Joo Lee,et al.  Influence zones for 2D pile–soil-tunnelling interaction based on model test and numerical analysis , 2007 .

[7]  Jianchen Wang,et al.  Analytical Solution of Ground Stress Induced by Shallow Tunneling with Arbitrary Distributed Loads on Ground Surface , 2019, Symmetry.

[8]  Yi Hong,et al.  Load transfer mechanism in pile group due to single tunnel advancement in stiff clay , 2015 .

[9]  Kuo-Hui Chiang,et al.  Responses of single piles to tunneling-induced soil movements in sandy ground , 2007 .

[10]  Yanyong Xiang,et al.  Theoretical prediction of the potential plastic zone of shallow tunneling in vicinity of pile foundation in soils , 2013 .

[11]  Harry G. Poulos,et al.  GROUND AND PILE-GROUP RESPONSES DUE TO TUNNELLING , 2001 .

[12]  C. J. LEE Numerical modelling of group effects on the distribution of dragloads in pile foundations , 2002 .

[13]  Cnlumhut Kutitrrattn,et al.  FORCE AT A POINT IN THE INTERIOR OF A SEMI-INFINITE SOLID , 2009 .

[14]  Alec M. Marshall,et al.  Tunnel-Pile Interaction Analysis Using Cavity Expansion Methods , 2012 .

[15]  Charles Wang Wai Ng,et al.  Development of Downdrag on Piles and Pile Groups in Consolidating Soil , 2004 .

[16]  Charles Wang Wai Ng,et al.  Three-dimensional centrifuge modelling of the effects of twin tunnelling on an existing pile , 2013 .