Ground settlement and fault deformation response to deep-buried tunnel excavation and groundwater drawdown

Construction technique considering the optimal sequence of pilot-tunnel excavation was investigated in order to ensure the safety of construction process of long-span shallow-buried tunnel. Firstly, optimal comparisons of the effect of different sequence of pilot-tunnel excavation on the ground settlement were implemented by the numerical analysis. Secondly, an optimal construction method was determined and applied to the construction of a practical tunnel. Some key issues and procedure of the selected construction method were described in detail. Finally, the numerical modeling and calculation of the tunnel construction process were conducted, and the effectiveness of these simulations was demonstrated by using the measured data of the practical tunnel.

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Calculation Model for Ground Settlement Process of Xi’an Subway Tunnel Non-Synchronous Excavation with Double-Line

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.90-93.2221 ◽

2011 ◽

Vol 90-93 ◽

pp. 2221-2225

Author(s):

Fang Tao She ◽

Sheng Jun Shao ◽

Juan Fang ◽

Yang Yang Jiao

Keyword(s):

Control Function ◽

Calculation Model ◽

Ground Settlement ◽

Subway Tunnel ◽

Tunnel Excavation ◽

Probability Curve ◽

Double Line ◽

Building Foundation ◽

Current Calculation ◽

Calculation Models

The current calculation models of ground settlement for tunnel excavation cannot reflect ground settlement of tunnel non-synchronous excavation with double-line. Based on the Peck ground settlement formula and Attewell ground settlement formula, displacement release of excavation place and tunnel non-synchronous excavation with double-line have researched. By means of finding a function to replace the accumulated probability curve, the new control function was beneficial to parameter introduced and improvement of the current ground settlement formula. By introducing the non-synchronous excavation distance and the displacement release coefficient of excavation place, A new calculation model for ground settlement process of tunnels non-synchronous excavation with double-line is proposed. The reliability and practical of the calculation models was verified. Research results were very important to analyze the ground settlement affecting the building foundation and pipe under ground.

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Three-dimensional numerical investigation of multifaced tunneling in water-bearing soft ground

Canadian Geotechnical Journal ◽

10.1139/t08-071 ◽

2008 ◽

Vol 45 (10) ◽

pp. 1467-1486 ◽

Cited By ~ 19

Author(s):

Chungsik Yoo ◽

Sun-Bin Kim

Keyword(s):

Numerical Investigation ◽

Three Dimensional ◽

Element Model ◽

Soft Ground ◽

Single Pile ◽

Ground Settlement ◽

Axial Loads ◽

Groundwater Drawdown ◽

Fully Coupled ◽

Ground Settlements

This paper presents the results of a numerical investigation of the performance of multifaced tunneling under a pile-supported building in water-bearing soft ground. Special attention was paid to the effect of tunneling and groundwater interaction on the tunneling performance. A fully coupled three-dimensional (3D) stress – pore pressure finite element model was adopted to realistically capture the mechanical and hydrological interaction between the tunneling and groundwater. The results indicate that the groundwater drawdown during tunneling yields a considerably larger settlement-affected zone than for cases with no groundwater drawdown, with a tendency for large portions of ground settlement and groundwater drawdown to be completed before the tunnel passes a monitoring section. Also revealed is that the presence of a building tends to reduce the ground settlements and cause subsurface settlements more or less uniformly with depth. It is shown that the lining deformation, and thus its stresses are not significantly affected by the presence of the building for the multifaced tunneling considered in this study. Axial loads in the piles supporting the building tend to either increase or decrease depending on the pile location relative to the tunnel axis. The patterns of changes in pile axial loads are different from the results of previous studies concerning a single pile.

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Numerical study of the effects of groundwater drawdown on ground settlement for excavation in residual soils

Acta Geotechnica ◽

10.1007/s11440-019-00843-5 ◽

2019 ◽

Vol 15 (5) ◽

pp. 1259-1272 ◽

Cited By ~ 10

Author(s):

A. T. C. Goh ◽

R. H. Zhang ◽

W. Wang ◽

L. Wang ◽

H. L. Liu ◽

...

Keyword(s):

Numerical Study ◽

Ground Settlement ◽

Residual Soils ◽

Groundwater Drawdown

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Analysis on Influence of Shield Tunneling on Bridge Double Pile

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.777.3 ◽

2015 ◽

Vol 777 ◽

pp. 3-7

Author(s):

Pei Sheng Xi ◽

Xiao Zhao ◽

Zhen Li

Keyword(s):

Horizontal Displacement ◽

Horizontal Direction ◽

Shield Tunnel ◽

Tunnel Construction ◽

Ground Settlement ◽

Lagrangian Analysis ◽

Shield Tunneling ◽

Tunnel Excavation ◽

Pile Deformation ◽

Main Deformation

Shield tunneling have varying degrees of impact on the surrounding buildings and the surrounding environment. Based on the shield tunneling of Hefei Subway Line 1 Ma'anshan viaduct, a 3D Fast Lagrangian Analysis of Continua is be used to simulate the shield tunnel construction and analyze the ground settlement and bridge pile deformation caused by tunnel construction. The numerical modeling results by analyzing the displacement variation and soil affected area at different distances show that when the shield tunnel excavation, the ground settlement becomes smaller with increasing distance from the shield center line of the pile and the maximum ground settlement is 10.778mm. The main deformation of bridge pile is in horizontal direction with a maximum horizontal direction of 2.0758mm. Horizontal displacement changes lager at the top of the pile, along with changes in the horizontal displacement of the pile depth becomes smaller, 15m is a turning point.

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