scholarly journals Study and Analysis of Pounding Effect between Adjacent RC Buildings

2019 ◽  
Vol 1 (1) ◽  
pp. 123-132
Author(s):  
A.D. Bhatt ◽  
G.P. Lamichhane
Keyword(s):  
Structural Damage ◽  
Separation Distance ◽  
Rc Buildings ◽  
Linear Dynamic ◽  
Adjacent Buildings ◽  
Gap Element ◽  
First Case ◽  
Adjacent Structures ◽  
Joint Displacement ◽  
Joint Acceleration

Pounding occurs when the adjacent buildings start vibration out of phase during the seismic activity which causes the collision between the adjacent structures. Due to higher cost of land in cities people have tendency to attach the buildings at property line. Earthquakes can cause pounding when adjacent buildings have little gap or no gap providing separation. Due to pounding effect structural and non – structural damage may occur in the adjacent buildings. The main objective of this research is to assess the seismic response of common residential RC buildings that has been constructed with no gap with the adjacent structures and to find the minimum gap requirement for the commonly constructed buildings of Nepal. For this study two different cases with varying separation distance between adjacent buildings have been considered. First case is the adjacent buildings having equal storey height but different number of stories. It includes models having 4 and 2 stories and 4 and 3 stories. Second case is the adjacent buildings having unequal storey height but same number of stories. It includes models having 3 and 3 stories and 4 and 4 stories. In both cases adjacent buildings have same material & sectional properties. Non-linear dynamic analysis is performed using El-centro earthquake data as ground motion. Gap element has been used to simulate the pounding force between buildings. Adjacent buildings having different overall height are modelled in SAP 2000 v 15 using gap element for pounding study. The seismic responses in terms of joint displacement, joint acceleration, pounding force are presented. Joint displacement and joint acceleration comparison for both pounding and no pounding cases are presented. Gap calculation from NBC and IS code, ABS and SRSS method was compared with gap required to avoid pounding force between adjacent structures and appropriate gap was recommended.

scholarly journals Effect of passive coupling on seismic interaction optimization of adjacent structures

2021 ◽  
Vol 25 (1) ◽  
pp. 99-110
Author(s):  
Khadidja Reteri ◽  
Abdellatif Megnounif
Keyword(s):  
Numerical Study ◽  
Separation Distance ◽  
Flexible Structure ◽  
Seismic Events ◽  
Rigid Structure ◽  
The Past ◽  
Adjacent Buildings ◽  
Coupling System ◽  
Adjacent Structures ◽  
Minimum Separation

Abstract During the past few years, several studies have been conducted in various fields of civil engineering in order to design structures that can withstand the forces and deformations that might occur during seismic events. However, more recently, building adjacent structures close to each other and more resistant to earthquakes, provided with coupling systems, has been an issue of major concern. The effects of some parameters, such as the characteristics of adjacent structures and those of the coupling system, on the choice of the separation distance, were investigated using a program that was developed using MATLAB. This article aims to present a study that is intended to determine the parameters characterizing the coupling system. Moreover, the influence of rigidity of the structure was also examined. For this, three examples were investigated: a flexible structure, a rigid structure, and a very rigid structure. The results obtained from the numerical study made it possible to show that knowing the characteristics, number, and arrangements of the coupling systems can be used to find the minimum separation distance between two adjacent buildings.

scholarly journals Research and Experiment on Optimal Separation Distance of Adjacent Buildings Based on Performance

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Hexian Luo ◽  
Qiaoyun Wu ◽  
Weijie Pan
Keyword(s):  
Seismic Vulnerability ◽  
Shaking Table Test ◽  
Separation Distance ◽  
Shaking Table ◽  
Frame Structures ◽  
Reinforced Concrete Frame ◽  
Scaled Model ◽  
Adjacent Buildings ◽  
Optimal Separation ◽  
Adjacent Structures

Firstly, constitutive models of two unequal height adjacent ten-story and six-story reinforced concrete frame structures were established based on OpenSees software in which a series of separation distances are set for incremental dynamic analysis (IDA), respectively. Secondly, the seismic vulnerability curves by postprocessing programming in Matlab software were obtained based on IDA datum, and the optimal separation distances of adjacent buildings with and without connecting dampers were obtained by comparing the seismic vulnerability of adjacent building at different separation distance and the seismic hazard analysis. Finally, a scaled model shaking table test of adjacent steel frame structures was performed. The conclusions are obtained by comparing the measured results of the test with those obtained by the OpenSees analysis, such as acceleration and displacement. The conclusions show that when two adjacent buildings are not connected with a damper, the distance of adjacent structures is suggested to be 0.3 m under moderate and strong earthquakes and the distance of adjacent structures is suggested to be a specified value of 0.24 m under rare earthquakes. When two adjacent buildings are connected with dampers, the separation distance is suggested to be 0.1 m under various performance conditions.

Comparison of Interstorey Drift in General RC Buildings in Pounding and No Pounding Case

2020 ◽  
Vol 2 (1) ◽  
pp. 40-47
Author(s):  
Anand Dev Bhatt
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Case Analysis ◽  
Rc Buildings ◽  
Adjacent Buildings ◽  
Sufficient Distance ◽  
Earthquake Load ◽  
Interstorey Drift ◽  
Lower Height

 Inter-storey drift is an important parameter of structural behavior in seismic analysis of buildings. Pounding effect in building simply means collision between adjacent buildings due to earthquake load caused by out of phase vibration of adjacent buildings. There is variation in inter-storey drift of adjacent buildings during pounding case and no pounding case. The main objective of this research was to compare the inter-storey drift of general adjacent RC buildings in pounding and no pounding case. For this study two adjacent RC buildings having same number of stories have been considered. For pounding case analysis there is no gap in between adjacent buildings and for no pounding case analysis there is sufficient distance between adjacent buildings. The model consists of adjacent buildings having 4 and 4 stories but unequal storey height. Both the buildings have same material & sectional properties. Fast non-linear time history analysis was performed by using El-centro earthquake data as ground motion. Adjacent buildings having different overall height were modelled in SAP 2000 v 15 using gap element for pounding case. Finally, analysis was done and inter-storey drift was compared. It was found that in higher building inter-storey drift is greater in no pounding case than in pounding case but in adjacent lower height building the result was reversed. Additionally, it was found that in general residential RC buildings maximum inter-storey drift occurs in 2nd floor.

Hysteresis Loops of Base Isolation System - An Overview

2021 ◽  
Vol 879 ◽  
pp. 189-201
Author(s):  
M.A. Amir ◽  
N.H. Hamid
Keyword(s):  
Earthquake Engineering ◽  
Structural Damage ◽  
Base Isolation ◽  
Numerical Models ◽  
Hysteresis Loops ◽  
Human Beings ◽  
Rc Buildings ◽  
Isolation System ◽  
Base Isolation System ◽  
Isolation Systems

Recently, there are a lot of technological developments in the earthquake engineering field to reduce structural damage and one of them is a base isolation system. The base isolation system is one of the best technologies for the safety of human beings and properties under earthquake excitations. The aim of this paper is to review previous research works on simulation of base isolation systems for RC buildings and their efficiency in the safety of these buildings. Base isolation decouples superstructure from substructure to avoid transmission of seismic energy to the superstructure of RC buildings. The most effective way to assess the base isolation system for RC building under different earthquake excitations is by conducting experiment work that consumes more time and money. Many researchers had studied the behavior of base isolation system for structure through modeling the behavior of the base isolation in which base isolator is modeled through numerical models and validated through experimental works. Previous researches on the modeling of base isolation systems of structures had shown similar outcomes as the experimental work. These studies indicate that base isolation is an effective technology in immunization of structures against earthquakes.

scholarly journals P169 Uterine leiomyoma extension into right side cardiac

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
K Diniz Ferrer ◽  
CARLOS Silveira ◽  
ADRIAN Reis ◽  
PAULA Abreu E Lima ◽  
ROBERT Diniz ◽  
...  
Keyword(s):  
Inferior Vena Cava ◽  
Right Atrium ◽  
Uterine Leiomyoma ◽  
Inferior Vena ◽  
Tumor Resection ◽  
Vena Cava ◽  
Cardiac Imaging Techniques ◽  
First Case ◽  
Adjacent Structures ◽  
The Right

Abstract Funding Acknowledgements governmental grants Uterine leiomyoma is a commom disease in women, however, intravenous leiomyomatosis of uterine origin extending via inferior vena cava into the right side of the heart,known as intracardiac leiomyomatosis is a rare condition (3%). In 1907, Durk reported the first case of intracardiac extension. The patient was a Woman, 35 years old, admitted to our emergency department for an intracardiac mass. She had shortness of breath,fatigue and chest pain. The transthoracic two dimensional echocardiography showed an echogenic oval mass mobile in right atrium and projected through right ventricle in diastole. This mass was observed to extend from inferior vena cava to the right atrium. The echotransesophageal three dimensional showed a large mobile mass that extended from inferior vena cava to the right atrium. A Computer tomographic (CT) scan showed a hypodense multilobulated mass in the pelvis, which had invaded the inferior vena cava and right atrium. The patient underwent a two stages surgery. In first stage (transatrial tumor resection). The operation was performed normal temperature with establisment of cardiopulmonary bypass (CPB). Subsequently, the pathological report was confirmed uterin smooth muscle origin. The second stage surgery ( total histerectomy) was done four weeks later for removing lobulated mass uterin with dimensions 20x15x7.5cm with confirmed histopathological of leiomyoma. Because of it is nonspecific clinical presentation and rarity, an intracardiac Leiomyomatosis continues to be a misdiagnosed as either thrombus or myxoma. The cardiac imaging techniques like a transthoracic echocardiography 2d and transesophageal echocardiography 3d have been used to define the presence, extension of tumor as appearance of the mass and involvement of adjacent structures. Abstract P169 Figure. Echotransesophageal 3D (bicaval view)

scholarly journals Three years with a knife stuck in the brain

2014 ◽  
Vol 33 (03) ◽  
pp. 192-196
Author(s):  
Luiz Coutinho Dias Filho ◽  
Alex Caetano de Barros ◽  
Marina Félix da Mota
Keyword(s):  
Informed Consent ◽  
Foreign Body ◽  
Postoperative Complications ◽  
Nervous Tissue ◽  
First Case ◽  
Adjacent Structures ◽  
Knife Blade ◽  
The Brain

AbstractCranial stabbing injuries penetrating the brain are not commonly encountered. The cases in which the knife is retained constitute a challenge to the neurosurgeon. When a long-term permanence occurs, the reaction to the presence of the foreign body causes adherence to the nervous tissue and a higher risk is expected from the removal. The procedure should be performed with meticulous dissection and minimal oscillation of the blade thus avoiding damage to the adjacent structures. We report a case of a man who remained three years with a knife blade deeply lodged in the brain. After obtaining informed consent, the blade was removed; there were no postoperative complications. To our knowledge, this is the first case in which, after years of permanence, a knife blade was removed from the brain through a craniotomy.

scholarly journals Investigating the effects of structural pounding on the seismic performance of adjacent RC and steel MRFs

2020 ◽  
Vol 19 (1) ◽  
pp. 317-343
Author(s):  
F. Kazemi ◽  
M. Miari ◽  
R. Jankowski
Keyword(s):  
Reinforced Concrete ◽  
Near Field ◽  
Limit State ◽  
Steel Structures ◽  
Lateral Force ◽  
Separation Distance ◽  
Natural Period ◽  
Performance Levels ◽  
Structural Pounding ◽  
Adjacent Structures

AbstractAn insufficient separation distance between adjacent buildings is the main reason for structural pounding during severe earthquakes. The lateral load resistance system, fundamental natural period, mass, and stiffness are important factors having the influence on collisions between two adjacent structures. In this study, 3-, 5- and 9-story adjacent reinforced concrete and steel moment resisting frames (MRFs) were considered to investigate the collision effects and to determine modification factors for new and already existing buildings. For this purpose, incremental dynamic analysis was used to assess the seismic limit state capacity of the structures using a developed algorithm in OpenSees software including two near-field record subsets suggested by FEMA-P695. The results of this paper can help engineers to approximately estimate the performance levels of MRFs due to pounding phenomenon. The results confirm that collisions can lead to the changes in performance levels, which are difficult to be considered during the design process. In addition, the results of the analyses illustrate that providing a fluid viscous damper between adjacent reinforced concrete and steel structures can be effective to eliminate the sudden changes in the lateral force during collision. This approach can be successfully used for retrofitting adjacent structures with insufficient in-between separation distances.

Structural Defects of Existing RC Buildings in Eskisehir Province

2011 ◽  
Vol 147 ◽  
pp. 145-148 ◽  
Author(s):  
A.Emre Cengiz ◽  
Yücel Güney ◽  
Onur Kaplan ◽  
Ahmet Topçu ◽  
Yunus Özçelikörs ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Steel Reinforcement ◽  
Structural Defects ◽  
Existing Buildings ◽  
Rc Buildings ◽  
Short Column ◽  
Adjacent Buildings ◽  
Long Span ◽  
Lateral Reinforcement

In this study, structural defects of existing 709 reinforced concrete (RC) buildings in Eskisehir Province were represented. Structural defects such as gaps between adjacent buildings, strong beam-weak column, mezzanine floor, short column, corner column, discontinuous frame, anchorage beams, long span, segregation, corrosion, inconvenient column/beam lateral reinforcement, low concrete strength and inconvenient steel reinforcement were determined in the study. It was determined that %35 of existing buildings have discontinuous frame, %16 of them have long span problem. It was also observed that nearly %40 of the buildings have no column/beam lateral reinforcement and %70 of them have inadequate gaps.

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