Development of an approximate method for analysis of connected buildings considering soil-structure interaction Balasaheb Ashok Konale ⇑ , Hemant Sharad Chore Department of civil engineering, Dr. B R Ambedkar National Institute of Technology, Jalandhar 144011, India article info Article history: Available online xxxx Keywords: Connected buildings Reinforced concrete bridge Irregular Time period Soil-structure interaction abstract Bridges connecting high-rise towers are becoming popular due to functional, architectural, and connec- tivity reasons in addition to the structural benefits they provide. Two regular adjacent buildings will become irregular with respect to certain modes when rigidly connected with a reinforced concrete bridge. The analysis of connected buildings for lateral loads is often complicated as it depends on the dynamic properties of the connecting towers and bridge. The design procedure for regular buildings according to earthquake codes will no longer be acceptable for connected buildings. For a realistic solu- tion, the superstructure-foundation-soil interaction must be considered as one compatible unit. The study presents an approximate method developed for the analysis of connected buildings considering soil-structure interaction. The actual building model with 3x3 bays and 10 stories as twin towers, with varying sizes of piles and the bridge, is modeled in ETABS and the structural response is obtained. An approximate model using a single tower with modifications of mass and stiffness coefficients at the level of connection is used to develop an analytical model in MATLAB. In each model, a fraction of the axial stiffness and mass of the bridge is considered from 0 to 20 at a regular interval of 0.5 and the closeness of the structural response to the actual is determined. The contribution of the stiffness and mass to be considered is varied and the closest match is determined. The study is repeated by varying the level of the bridge, diameter of the pile, and the width of the bridge from a single bay to three bays and inferences drawn. Ó 2024 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Confer- ence on Advances in Construction Materials and Structures. 1. Introduction With the increased construction of tall buildings, there is a growing trend of connecting individual towers by a connecting bridge which serves a multitude of purposes. There is also a trend worldwide from an aesthetic point of view that the neighbouring tall buildings are designed as linked buildings, i.e., towers horizon- tally connected by links such as sky bridges, sky gardens, etc. Some of the interconnected buildings constructed worldwide are Chongqing’s ’horizontal skyscraper’ in China, Marina Bay Sands linked structure in Singapore, China Media Group Headquarters, Nation Towers in Abu Dhabi, etc. If two adjacent buildings are rigidly connected by a reinforced concrete bridge, it will modify the dynamic response of the struc- ture to lateral loads. In fact, buildings especially those with differ- ent dynamic properties respond differently during an earthquake. i.e., its structural behaviour may become quite different from the buildings considered individually. Along with this, the foundation’s base is assumed to be fixed in the conventional design process, which neglects the foundation’s flexibility and the subsoil’s ability to compress. In many practical cases, the towers are constructed individually and the connecting bridge is built only at a later stage. This introduces additional forces which were not considered ini- tially. The presence of soil structure interaction further complicates the scenario as it modifies the seismic response of the structure. Consequently, it is necessary to conduct an interaction analysis to determine the influence of soil-structure interaction on the response of both buildings which are supported on pile founda- tions embedded in a cohesive soil and subjected to lateral loads. The Petronas twin towers in Kuala Lumpur are an example of a reinforced concrete bridge being an integral part of a fire evacua- tion. Wilson, and Elm. Bethesda in Maryland, U.S. as shown in Fig. 1. https://doi.org/10.1016/j.matpr.2023.03.497 2214-7853/Ó 2024 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Advances in Construction Materials and Structures. ⇑ Corresponding author. E-mail address: balasahebkonale@gmail.com (B.A. Konale). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: B.A. Konale and H.S. Chore, Development of an approximate method for analysis of connected buildings considering soil-structure interaction, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2023.03.497