Effects Of Urban Tunnel Excavation In Tehran In Response To Existing Static And Dynamic Structures In Terms Of Soil And Structure Interaction.

Document Type : Research Article

Authors

1 Instructor of Razi Technical School of Ardabil

2 Isfahan University of Technology

3 PhD student of Structural Engineering, Zanjan University, Razi University of Technology, Ardabil

Abstract

Abstract
Excavation of tunnels can cause the earth to move, which is significant in the static and dynamic response of structures. In this study, the effect of a tunnel excavation in Tehran city on the dynamic and static response of structures in three section has been investigated. In the first part, PLAXIS software calculates the following two step session before and after excavating. The second part of PLAXIS also performs dynamic analysis for both stages and the following acceleration response is calculated. The purpose of the second part is to investigate the impact of excavating on acceleration response and its use in SAP 2000 software as input for structural analysis. In the third part, structure in modeled in SAP 2000 software and the results of the first part of the displacements of footing are applied and by using accelerating response, the structure`s nonlinear dynamic analysis is performed in two stages (PLAXIS output). The results of the analysis show that the tunnel excavation has increased the subsidence of foundation subsurface and the highest subsidence is in 6th model (Operation stage), which is 1.2 times the average of the previous one. The excavation has increased and the impact of the supporting structures during the execution phase compared to the operation stage where the concrete side walls are executed, has been effective in reducing the subsidence by 4% and maximizing the acceleration below 1.5 times and also in the structures the displacement increased by 1.25 times compared to the pre excavation phase response.

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