Tunnel Analysis of Dhaka Subway using PLAXIS 2D Considering Different Groundwater Level Conditions
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Department of Civil and Environmental Engineering (CEE), Islamic University of Technology(IUT)
Abstract
Dhaka subway, which will be an underground structure is being considered to combat the
rising congestion in the city. As the city is very congested special consideration must be
given to ground movement and surface settlement during the planning of the subway. Also,
the rise in water level as the city moves away from groundwater for its water supply must
also be taken into consideration for the long-term design of the tunnel. In this study, 2D finite
element analysis was carried out using Plaxis 2D. Different soil profile representing different
areas of the Dhaka city was considered and the surface settlement due to tunnel excavation
was investigated. It was found that as the depth of the tunnel excavation increases the surface
settlement decreases and the settlement trough becomes wider. Also, the volume loss and the
grouting pressure required for a specific surface settlement after the tunnel was constructed
was also studied and it was found that both volume loss and grouting pressure required
increases with the depth of the tunnel. And also, the lining stresses of the tunnel considering
different groundwater conditions was analyzed. It was found that as depth of tunnel increases
the axial forces experienced by the tunnel lining increases. Also, the axial forces, bending
moments and shear forces mostly increases as the ground water level increases in the future.
Description
Supervised by
Prof. Dr. Hossain Md. Shahin
Department of Civil and Environmental Engineering(CEE),
Islamic University of Technology(IUT),
Board Bazar, Gazipur-1704. Bangladesh
This thesis is submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Civil and Environmental Engineering, 2022
Keywords
Dhaka Subway, Tunnel, Surface settlement, Settlement trough, Ground behavior, Volume loss, Ground Water Level, Finite Element Analysis, Plaxis 2D, Lining stresses
Citation
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