International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 03 | Mar -2017
p-ISSN: 2395-0072
www.irjet.net
Seismic Pounding of Adjacent Buildings Vidhya P Namboothiri1 1MTech
IInd year student, Dept. of Civil Engineering, SreeBuddha College of Engineering, Kerala, India
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Abstract - In recent years, the pounding of the adjacent
that could suffer pounding damage in future earthquakes. Building structures are often built close to each other as in the case of residential building complexes or in downtown of metropolitan cities where the cost of land is high. Due to the close proximity of these structures, they have often been found to impact each other while responding to earthquake induced strong ground motion. An earthquake can cause sudden movement of the ground that is transferred to the structure through foundation
structures has been receiving considerable attention during the earthquake because such structures with inadequate clear spacing between them suffers structural and nonstructural damage as a result of collision during earthquake. An expansion joint separates such adjacent buildings which is insufficient to accommodate the lateral movements of buildings under earthquakes. Seismic pounding can be prevented by providing adequate separation distances as specified in the safe code. Sometimes, getting the required safe separations is not possible in metropolitan areas because of the high land value, limited availability of land space and the need for centralized facilities under one roof encourages buildings to be built very close to each other ignoring the effect of seismic pounding during the design. If building separations in metropolitan areas are found to be deficient to prevent pounding, then there should be some secure and cost-effective retrofitting methods to mitigate its effect. The objective is to understand the consequences of seismic pounding on the performance of structural and nonstructural components in building.
The highly congested building system in many metropolitan cities constitutes a major concern for seismic pounding damage. For these reasons, it has been widely accepted that pounding is an undesirable phenomenon that should be prevented or mitigated zones in connection with the corresponding design ground acceleration values will lead in many cases to earthquake actions which are remarkably higher than defined by the design codes used up to now. The most simplest and effective way for pounding mitigation and reducing damage due to pounding is to provide enough separation but it is sometimes difficult to be implemented due to detailing problem and high cost of land. An alternative to the seismic separation gap provision in the structure design is to minimize the effect of pounding through decreasing lateral motion which can be achieved by joining adjacent structures at critical locations so that their motion could be in-phase with one another or by increasing the pounding buildings damping capacity by means of passive structural control of energy dissipation system or by seismic retrofitting.
Key Words: Structural pounding, Building collision, Adjacent buildings, Seismic separation distance, Pounding analysis
1.INTRODUCTION The Seismic Pounding can be defined as the collision of adjacent buildings during the earthquakes. This phenomenon is mostly observed in the old buildings which were constructed in the years before earthquake resistant design principles became popular. The principle reason for the pounding effect is the insufficient gap in between the adjacent buildings. Although many current codes specifies a minimum seismic gap, it is still inadequate since the codes necessarily lag behind the current researches and fail to include the effect of other parameters that affect the structural deformation.
Fig-1: Pounding of Adjacent Buildings
1.1 Causes of Pounding
Pounding of adjacent buildings may also have worse damage when adjacent buildings with different dynamic characteristics vibrates out of phase and when there is insufficient separation distance. Past seismic codes did not give definite guidelines to preclude pounding, due to economic considerations including maximum and usage requirements, especially in the high density populated areas of cities, there are many buildings worldwide which are already built in contact or extremely close to another,
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Impact Factor value: 5.181
The various causes of pounding are as follows: Adjacent buildings with the same heights and the same door levels Adjacent buildings with same floor levels but different heights Adjacent structures with different total height and floor levels Structures are situated in a row
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