• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.219-224
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• 2016

The vibration control performance of a semi-active damper connected to adjacent buildings subjected to seismic loads was investigated. The MR damper was used as a semi-active control device. A fuzzy logic control algorithm was used for effective control of the adjacent buildings connected to the MR damper. In the buildings control coupled with a MR damper, the response reduction of one building results in an increase in the response in another building. Because of these conflict characteristics, multi-objective optimization is required. Therefore, a fuzzy logic control algorithm for the control of a MR damper was optimized using a multi-objective genetic algorithm. Based on numerical analyses, the semi-active fuzzy control of MR damper for adjacent coupled buildings can provide good control performance.

• Journal of Korean Association for Spatial Structures
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• v.15 no.2
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• pp.105-112
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• 2015

A shared tuned mass damper (STMD) was proposed in previous research for reduction of dynamic responses of the adjacent buildings subjected to earthquake loads. A single STMD can provide similar control performance in comparison with two traditional TMDs. In previous research, a passive damper was used to connect the STMD with adjacent buildings. In this study, a smart magnetorheological (MR) damper was used instead of a passive damper to compose an adaptive smart STMD (ASTMD). Control performance of the ASTMD was investigated by numerical analyses. For this purpose, two 8-story buildings were used as example structures. Multi-input multi-output (MIMO) fuzzy logic controller (FLC) was used to control the command voltages sent to two MR dampers. The MIMO FLC was optimized by a multi-objective genetic algorithm. Numerical analyses showed that the ASTMD can effectively control dynamic responses of adjacent buildings subjected to earthquake excitations in comparison with a passive STMD.

• Earthquakes and Structures
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• v.1 no.3
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• pp.231-252
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• 2010

Previous research on pounding between seismically isolated buildings during earthquakes has been focused on impacts at the bases of structures and the effect of simultaneous interactions at the bases and at the superstructures has not been studied in details. In this paper, the seismic responses of adjacent buildings supported on different or similar base systems considering impacts between bases and superstructures are numerically investigated. The study is carried out in three parts for the two types of adjacent buildings: (i) both structures have fixed bases; (ii) one structure has fixed base and the other is seismically isolated and (iii) both structures have base isolation systems. The results of the study indicate that the pounding-involved responses of the buildings depend mainly on the type of structural base systems and on the structural parameters of both buildings. For the base-isolated building, the variation of the peak accelerations and displacements of the storeys have been found to be relatively low. On the other hand, significant differences have been observed for the fixed base building. The results of the parametric study conducted for different values of the gap size between colliding structures show the reduction in the peak base displacements as the gap distance decreases.

• Earthquakes and Structures
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• v.26 no.6
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• pp.477-487
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• 2024

The interaction between multiple structures through the supporting soil media, known as structure-soil-structure interaction (SSSI), has become an increasingly important issue due to rapid urbanization. There is a need to investigate the effect of SSSI on the structural response of buildings compared to non-interaction analysis (NIA) and soil-structure interaction (SSI) analysis. In the present study, two identical 4-bay×4-bay, three-story RCC buildings are modeled adjacent to each other with a soil domain beneath it to investigate the effect of SSSI on the forces experienced by footings under gravity and seismic load cases. The ANSYS software is used for modeling various non-interaction and interaction models which work on the principle of FEM. The results indicate that in most of the footings, the SSSI effect causes a significant redistribution of forces compared to SSI and NIA under both gravity and seismic load cases. The maximum interaction effect is observed on the footings that are closer to the adjacent building. The axial force, shear force and bending moment values on these footings show that SSI causes a significant increase in these values compared to non-interaction analysis but the presence of adjacent building relieves these forces significantly.

• Earthquakes and Structures
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• v.18 no.6
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• pp.667-675
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• 2020

The current study compares the effect of structure-soil-structure interaction (SSSI) on the dynamic responses of adjacent buildings and isolated structures including soil-structure interaction (SSI) with the responses of fixed-base structures. Structural responses such as the relative acceleration, displacement, drift and shear force were considered under earthquake ground motion excitation. For this purpose, 5-, 10- and 15-story structures with 2-bay moment resisting frames resting on shallow foundations were modeled as a group of buildings in soft soil media. Viscous lateral boundaries and interface elements were applied to the soil model to simulate semi-infinite soil media, frictional contact and probable slip under seismic excitation. The direct method was employed for fully nonlinear time-history dynamic analysis in OpenSees using 3D finite element soil-structure models with different building positions. The results showed that the responses of the grouped structures were strongly influenced by the adjacent structures. The responses were as much as 4 times greater for drift and 2.3 times greater for shear force than the responses of fixed-base models.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.4
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• pp.433-442
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• 2004

The aim of this paper is to study the interaction between adjacent buildings with different foundation levels under earthquake loading conditions. Buildings and soil are represented by two different models. In the first case, the building itself is modeled with standard frame element, whereas the soil behavior is stimulated by a special grid model. In the second case, the building and soil are represented by plane stress or plane strain elements. The modulus of elasticity of the 9round as well as the varying relations of inertia have a strong influence on the section forces within the buildings. The Interaction between the two buildings is demonstrated and discussed via numerical examples using the proposed method.

• Earthquakes and Structures
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• v.22 no.3
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• pp.289-304
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• 2022

During strong ground motions, adjacent structures with insufficient separation distances collide with each other causing considerable architectural and structural damage or collapse of the whole structure. Generally, existing design procedures for determining the separation distance between adjacent buildings subjected to structural pounding are based on approximations of the buildings' peak relative displacement. These procedures are based on unknown safety levels. This paper attempts to evaluate the influence of foundation flexibility on the structural seismic response by considering the variability in the system and uncertainties in the ground motion characteristics through comprehensive numerical simulations. Actually, the aim of this study is to evaluate the influence of foundation flexibility on probabilistic evaluation of structural pounding. A Hertz-damp pounding force model has been considered in order to effectively capture impact forces during collisions. In total, 5.25 million time-history analyses were performed over the adopted models using an ensemble of 25 ground motions as seismic input within OpenSees software. The results of the study indicate that the soil-structure interaction significantly influences the pounding-involved responses of adjacent structures during earthquakes and generally increases the pounding probability.

• Earthquakes and Structures
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• v.23 no.2
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• pp.151-168
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• 2022

Torsion is one of the most important causes of building collapse during earthquakes. Sometimes, despite the symmetric form of the building, infill walls disturb the symmetry of the lateral resisting system. The purpose of this research is to investigate the effect of urban layout on developing torsion caused by infill walls. For this purpose, a typological study was conducted based on the conditions of perimeter walls on 364 buildings and then 9 cases were selected. The dimensions of the selected buildings are constant and the conditions of the perimeter walls including facades with openings and cantilevered facades are variable. The selected buildings with 60 different layouts of infill walls were analyzed and the behavior of each one was evaluated based on the torsional irregularity criteria of seismic codes. The results of the analyses showed that if the perimeter walls of a building are symmetric, asymmetric interior walls will not be important in developing torsion and effective parameters in symmetry of the perimeter infill walls are the number of walls, area of openings, aspect ratio, and construction details. Finally, architectural solutions to mitigate the torsional effects of infill walls were proposed for buildings with solid infill walls on some sides, for buildings where the perimeter walls of one side are on the cantilevered part, and for buildings where the perimeter walls of two adjacent sides are on the cantilevered part. In three-sided buildings, where two adjacent façades are cantilevered, it is often impossible to use the potential of the infill walls.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.4
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• pp.3-12
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• 2011

This study investigates interior and exterior environments and arrangement forms of school buildings from elementary to high school which were recently built in Daegu since the 7th Educational Curriculum. In addition, this study analyses how outside noise affects inside environment of schools. This study found that the noise level criteria of school facilities(such as exterior learning sites and outer walls of school buildings) adjacent to street of one side satisfiedly corresponded to the level and criteria, 65dB(A), of school health law. However, the noise level and vibration criteria of school facilities adjacent to street of two sides did not satisfiedly corresponded to the level or criteria, 65dB(A). In case of classrooms, the inner noise of educational facilities with windows closed and also close to both the street of one side and of two sides satisfiedly corresponded to the level or criteria. 55dB(A), of school health law. In spring and tall, the windows are more open them usual for ventilation, and leaving windows open can lead to noise from outside. Thus, it is urgent to prepare for this situation.

• Structural Engineering and Mechanics
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• v.51 no.2
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• pp.277-297
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• 2014

Since the isolation bearings undergo large displacements in base-isolated structures, impact with adjacent structures is inevitable. Therefore, in this investigation, the effect of impact on seismic response of isolated structures mounted on double concave friction pendulum (DCFP) bearings subjected to near field ground motions is considered. A non-linear viscoelastic model of collision is used to simulate structural pounding more accurately. 2-, 4- and 8-story base-isolated buildings adjacent to fixed-base structures are modeled and the coupled differential equations of motion related to these isolated systems are solved in the MATLAB environment using the SIMULINK toolbox. The variation of seismic responses such as base shear, displacement in the isolation system and superstructure (top floor) is computed to study the impact condition. Also, the effects of variation of system parameters: isolation period, superstructure period, size of seismic gap between two structures, radius of curvature of the sliding surface and friction coefficient of isolator are contemplated in this study. It is concluded that the normalized base shear, bearing and top floor displacement increase due to impact with adjacent structure. When the distance between two structures decreases, the base shear and displacement increase comparing to no impact condition. Besides, the increase in friction coefficient difference also causes the normalized base shear and displacement in isolation system and superstructure increase in comparison with bi-linear hysteretic behavior of base isolation system. Totally, the comparison of results indicates that the changes in values of friction coefficient have more significant effects on 2-story building than 4- and 8-story buildings.