Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-4-2013

Abstract

The development of cities requires the use of underground area for the construction of transportation infrastructure facilities. Construction of twin tunnels or new tunnel close to the existing ones may be done horizontally, vertically or in inclined manner. In the case of horizontal tunnels the distribution of tunnel load will be more in lateral direction. Since cities are densely concentrated with tall structures, laterally distributed loads will induce settlement in the foundation of the structures. For a particular orientation of tunnels, the soil movement and internal forces in the lining will be affected by both the relative position of tunnels and the construction procedure. Hence the study on influence of these factors on the tunnel design gains importance. In the present study a numerical analysis has been carried out to evaluate the relative position of the twin tunnels in three directions in layered soil. The direction considered are horizontal alignment, vertical alignment and inclined alignment. Model twin tunnels have been constructed using numerical code Plaxis based on finite element analysis. Settlement analysis has been carried out for the different loading conditions on the tunnels in the selected directions. The results are presented in the form of surface settlement, bending moment and stresses in the lining of the tunnels for different orientation of tunnels. The construction of upper tunnel at first leads to both higher settlement and bending moment. The highest soil settlement is obtained for vertical aligned tunnels, while horizontal aligned tunnels cause the lowest settlement.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 29th, 12:00 AM May 4th, 12:00 AM

Influence of Relative Position of the Tunnels: A Numerical Study on Twin Tunnels

Chicago, Illinois

The development of cities requires the use of underground area for the construction of transportation infrastructure facilities. Construction of twin tunnels or new tunnel close to the existing ones may be done horizontally, vertically or in inclined manner. In the case of horizontal tunnels the distribution of tunnel load will be more in lateral direction. Since cities are densely concentrated with tall structures, laterally distributed loads will induce settlement in the foundation of the structures. For a particular orientation of tunnels, the soil movement and internal forces in the lining will be affected by both the relative position of tunnels and the construction procedure. Hence the study on influence of these factors on the tunnel design gains importance. In the present study a numerical analysis has been carried out to evaluate the relative position of the twin tunnels in three directions in layered soil. The direction considered are horizontal alignment, vertical alignment and inclined alignment. Model twin tunnels have been constructed using numerical code Plaxis based on finite element analysis. Settlement analysis has been carried out for the different loading conditions on the tunnels in the selected directions. The results are presented in the form of surface settlement, bending moment and stresses in the lining of the tunnels for different orientation of tunnels. The construction of upper tunnel at first leads to both higher settlement and bending moment. The highest soil settlement is obtained for vertical aligned tunnels, while horizontal aligned tunnels cause the lowest settlement.