International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 11 Issue: 05 | May 2024
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p-ISSN: 2395-0072
Performance Evaluation of Multi-Storey Building Subjected to Static and Dynamic Load Resting Above Tunnel In Stratified Soil. Likhitha M1, L Govindaraju2 1Post graduate student, Dept. of civil engineering, UVCE Bangalore University, Bengaluru 2Professor, Dept. of Civil Engineering, UVCE Bangalore University, Bengaluru
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Abstract - This study presents a comprehensive numerical
earthquake data. Assessing the settlement impact of the building's offset ranging from 0 to 20 meters from the tunnel centerline, and determining the acceleration at the top and bottom of the building resulting from the dynamic loads.
investigation into the settlement behavior of multi-storey buildings with basements situated above unlined rectangular tunnels within stratified soil. The analysis encompasses configurations with 3 bay building directly positioned a top the tunnel as well as those with an offset varying from 5m to 20m at 5m intervals. Employing the finite element software PLAXIS-2D, both static and dynamic analyses are conducted, with the dynamic analysis incorporating the time history of the 2001 Bhuj earthquake. The results indicate that the settlement behavior of the buildings can be successfully analyzed using the finite element method. This study provides valuable insights into the settlement behavior of buildings above unlined tunnels and offers implications for design and analysis considerations in similar geotechnical contexts. The findings suggest that the presence of an unlined tunnel can significantly impact the settlement behavior of buildings.
1.1 Finite Element Analysis PLAXIS is a finite element package that has been developed specifically for the analysis of deformation, stability and flow in geotechnical engineering projects. The program is designed to simulate the behavior of soil, rock, and other geomaterials under various loading conditions, making it an indispensable tool for engineers and researchers working in the field of geotechnical engineering. At the core of PLAXIS 2D is its ability to model the complex, non-linear behavior of geomaterials. The software incorporates a comprehensive library of advanced soil and rock constitutive models, including the Mohr-Coulomb, Hardening Soil, and Soft Soil models, among others. These constitutive models enable users to accurately represent the stress-strain relationships, consolidation, and other fundamental properties of the materials being analyzed, ensuring the reliability and accuracy of the simulation results.
Key Words: Stratified Soil, Unlined tunnel, Time history analysis, Finite element analysis (FEM), PLAXIS-2D
1. INTRODUCTION In the Metropolitan cities due to lack of land for the infrastructure improvement/ development like the roadways, railways, sewer lines, communication cables etc., are going underground. If the buildings or any other structures built above these underground structure will have impact on the stability of the structures. Foundation plays a very impotent role in carrying the load from the super structure to substructure. The substructure is nothing but the underlying soil. The load received from the foundation is distributed to wide area below the foundation. The soil is an elastic medium which is good at taking the compression load. The below soil may fail due to two Criteria’s either it may fails due to excessive settlement or bearing capacity failure. The existence of underlying voids has a negative impact on the ultimate bearing capacity and the settlement behaviour of shallow foundations.
2. PROBLEM STATEMENT The model comprises four layers of soil, extending from 0 meters to a depth of 100.1 meters. At a depth of 60.8 meters, there is a rectangular unlined tunnel measuring 13.65 meters in width and 12.27 meters in depth. The building's height ranges from 15 to 30 meters for 2-bay building configuration. The basement height varies, with floor tofloor heights of 2 meters and 3 meters respectively. Each bay has a width of 5 meters as represented in the figure (1). The soil comprises four distinct layers, each with specified properties as outlined in Table-1. For the building materials, plate elements are utilized for the basement and the remainder of the structure, with properties detailed in Table-2. Additionally, columns within the building are represented to separate bays node to node, with their properties specified in Table-3.
In the present study, a multi-storey building resting above a rectangular unlined tunnel in a stratified soil was analyzed using a finite element-based numerical analysis geotechnical software, PLAXIS 2D, with the primary objectives of investigating the settlement behavior of a 3-bay building under static loading, analyzing its settlement behavior under dynamic loading using the 2001 Bhuj
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