Seismic Vulnerability of Reinforced Concrete Frame with Unreinforced Masonry Infill Due to Main Shock–Aftershock Earthquake Sequences

2015 ◽  
Vol 31 (3) ◽  
pp. 1427-1449 ◽  
Author(s):  
Solomon Tesfamariam ◽  
Katsuichiro Goda ◽  
Goutam Mondal
Keyword(s):  
Reinforced Concrete ◽  
Seismic Vulnerability ◽  
Main Shock ◽  
Ground Motions ◽  
Period Change ◽  
Reinforced Concrete Frame ◽  
Site Class ◽  
Concrete Frame ◽  
Rc Frames ◽  
Hazard Level

This paper presents a parametric study on the inelastic response of six-story reinforced concrete (RC) frames subjected to main shock–aftershock (MS-AS) ground motions. For this purpose, one bare frame (BF) and four masonry RC frames with two infill thicknesses (75 mm or 125 mm) and two infill patterns (open ground story or fully infilled) are considered. They are situated at site class C in Vancouver, Canada, and are designed for office occupancy according to the 2005 National Building Code of Canada. The five frames are subjected to 100 ensembles of MS-AS ground motions scaled to seismic hazard level corresponding to the return period of 2,500 years. For each sequence of earthquakes, change in the fundamental period ( T1) and inter-story drift (ISD) for both MS-AS sequences are quantified. The analysis results show that the period change and ISD were significant for BF, whereas the infilled frames sustained small damage with negligible change in T1.

scholarly journals Challenges in Evaluating Seismic Collapse Risk for RC Buildings

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Jin Zhou ◽  
Zhelun Zhang ◽  
Tessa Williams ◽  
Sashi K. Kunnath
Keyword(s):  
Ground Motion ◽  
Seismic Vulnerability ◽  
Ground Motions ◽  
Primary System ◽  
Fragility Functions ◽  
Reinforced Concrete Frame ◽  
Ground Motion Selection ◽  
Concrete Frame ◽  
Frame Building ◽  
Seismic Collapse

AbstractThe development of fragility functions that express the probability of collapse of a building as a function of some ground motion intensity measure is an effective tool to assess seismic vulnerability of structures. However, a number of factors ranging from ground motion selection to modeling decisions can influence the quantification of collapse probability. A methodical investigation was carried out to examine the effects of component modeling and ground motion selection in establishing demand and collapse risk of a typical reinforced concrete frame building. The primary system considered in this study is a modern 6-story RC moment frame building that was designed to current code provisions in a seismically active region. Both concentrated and distributed plasticity beam–column elements were used to model the building frame and several options were considered in constitutive modeling for both options. Incremental dynamic analyses (IDA) were carried out using two suites of ground motions—the first set comprised site-dependent ground motions, while the second set was a compilation of hazard-consistent motions using the conditional scenario spectra approach. Findings from the study highlight the influence of modeling decisions and ground motion selection in the development of seismic collapse fragility functions and the characterization of risk for various demand levels.

scholarly journals Assessment of Seismic Vulnerability of Reinforced Concrete Frame buildings

2018 ◽  
Vol 149 ◽  
pp. 02036
Author(s):  
Cherifi Fatiha ◽  
Farsi Mohammed ◽  
Kaci Salah
Keyword(s):  
Reinforced Concrete ◽  
Seismic Vulnerability ◽  
Reinforced Concrete Frame ◽  
Nonlinear Method ◽  
Seismic Risk Analysis ◽  
Building Inventory ◽  
Concrete Frame ◽  
Capacity Curves ◽  
The North ◽  
Frame Buildings

The seismic activity remains strong in the north of Algeria since no less than 30 earthquakes per month are recorded. The large number of structures built before the introduction of the seismic standards represents a high seismic risk. Analysis of damage suffered during the last earthquakes highlighted the vulnerability of the existing structures. In this study the seismic behavior of the existing buildings in Tizi-Ouzou city, located in the north of Algeria, is investigated. To make this assessment, a database was created following a building inventory based on a set of technical folders and field visits. The listed buildings have been classified into different typologies. Only reinforced concrete frame buildings are considered in this paper. The approach adopted to estimate structures damage is based on four main steps: 1) construction of capacity curves using static nonlinear method “push-over”, 2) estimate of seismic hazard, 3) determination of performance points, and finally 4) deduction of damage levels.

Response of Mid-Rise Reinforced Concrete Frame Buildings to the 2017 Puebla Earthquake

2019 ◽  
Vol 35 (4) ◽  
pp. 1763-1793 ◽  
Author(s):  
Carlos A. Arteta ◽  
Julian Carrillo ◽  
Jorge Archbold ◽  
Daniel Gaspar ◽  
Cesar Pajaro ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
The United States ◽  
Rc Buildings ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Soft Story ◽  
Masonry Infills ◽  
Rc Frames ◽  
Ductility Capacity

The response of mid-rise reinforced concrete (RC) buildings in Mexico City after the 2017 Puebla Earthquake is assessed through combined field and computational investigation. The Mw 7.1 earthquake damaged more than 500 buildings where most of them are classified as mid-rise RC frames with infill walls. A multinational team from Colombia, Mexico, and the United States was rapidly deployed within a week of the occurrence of the event to investigate the structural and nonstructural damage levels of over 60 RC buildings with 2–12 stories. The results of the study confirmed that older mid-rise structures with limited ductility capacity may have been shaken past their capacity. To elucidate the widespread damage in mid-rise RC framed structures, the post-earthquake reconnaissance effort is complemented with inelastic modeling and simulation of several representative RC framing systems with and without masonry infill walls. It was confirmed that the addition of non-isolated masonry infills significantly impacts the ductility capacity and increases the potential for a soft-story mechanism formation in RC frames originally analyzed and designed to be bare systems.

SEISMIC RETROFIT OF NONDUCTILE REINFORCED CONCRETE FRAME AND MASONRY BUILDINGS

2019 ◽  
Vol 2 (Special Issue on First SACEE'19) ◽  
pp. 143-164
Author(s):  
Murat Saatcioglu
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Seismic Retrofit ◽  
Masonry Wall ◽  
System Level ◽  
Reinforced Concrete Frame ◽  
Existing Building ◽  
Concrete Frame

A large proportion of existing building and bridge infrastructure across the world consists of seismically deficient non-ductile structural systems. Performance of structures during recent earthquakes have demonstrated seismic vulnerability of these systems, the majority of which were designed prior to the enactment of modern seismic codes, though some were designed more recently in areas where code enforcement provides challenges. These structures constitute considerable seismic risk, especially in large metropolitan centres. Because it is economically not feasible to replace a large segment of seismically deficient infrastructure with new and improved systems, retrofitting existing structures remains to be a viable seismic risk mitigation strategy. The objective of this paper is to highlight seismic retrofit strategies for deficient building and bridge infrastructures, with emphasis on experimental and analytical research conducted at the University of Ottawa. The retrofit strategies consist of structural upgrades at the system level, as well as at the element level. Non-ductile reinforced concrete frame retrofits, in the form of lateral bracing techniques, and concrete column and masonry wall retrofit methodologies are discussed. The use of innovative materials and techniques are presented.

Quantifying the Reduction in Collapse Safety of Main Shock–Damaged Reinforced Concrete Frames with Infills

2017 ◽  
Vol 33 (1) ◽  
pp. 25-44 ◽  
Author(s):  
Henry V. Burton ◽  
Mayank Sharma
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Analysis ◽  
Main Shock ◽  
Limit State ◽  
Incremental Dynamic Analysis ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Frame Buildings ◽  
Story Drift

A performance-based methodology is presented to quantify the reduction in collapse safety of main shock–damaged reinforced concrete frame buildings with infills. After assessing their collapse safety in the intact state, the residual collapse capacity following main shock damage is evaluated by conducting incremental dynamic analysis to collapse using main shock–aftershock ground motion sequences. The median collapse capacity and conditional probability of collapse for the main shock–damaged building, normalized by that of the intact case are the metrics used to measure the reduction in collapse safety. Taller buildings with built-in soft and weak first stories have the highest reduction in collapse safety as a result of main shock damage. Among the engineering demand parameters recorded during the main shock analyses, story drift demands (peak transient and residual) and infill strut axial deformations have the highest correlation with the decline in collapse performance. The results of the main shock–aftershock incremental dynamic analysis to collapse are used to develop fragility functions for the limit state defined by the building being structurally unsafe to occupy.

Seismic response analyses and performance assessment of masonry-infilled reinforced concrete frame buildings in Bhutan without and with soft storey

2016 ◽  
Vol 20 (5) ◽  
pp. 822-839
Author(s):  
Kinzang Thinley ◽  
Hong Hao
Keyword(s):  
Reinforced Concrete ◽  
Return Period ◽  
Ground Motions ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Soft Storey ◽  
Concrete Frame ◽  
Seismic Design Code ◽  
Frame Buildings ◽  
High Seismicity

Bhutan locates in a high seismicity region but has no seismic design code of its own. Recent devastating earthquake in Nepal, which is located in the same region as Bhutan and with similar construction types, raises the concern on the seismic safety of building structures in Bhutan. This study is aimed at assessing the performance of masonry-infilled and soft storey reinforced concrete frame buildings in Bhutan under the 475- and 2475-year return period ground motions predicted from the Probabilistic Seismic Hazard Analysis. A nonlinear strut model is used to model the infill wall, and the influence of openings and soil–structure interaction are considered in the analyses. The result suggests that the masonry-infilled reinforced concrete frame buildings in Bhutan could suffer repairable and irreparable damages under the 475-year return period ground motions and severe damages and even collapse under the 2475-year return period ground motion. The buildings with the soft storey are found to be more vulnerable than the normal masonry-infilled reinforced concrete buildings. The design recommendation of Indian Seismic Code improves the performance of soft storey buildings but cannot fully negate the soft storey effect. This study is the first such effort in assessing the performance of general building stocks in the high seismicity Bhutan. The results can guide the seismic strengthening options and can be used for further loss predictions for seismic preparedness of the country.

scholarly journals Factors in the Relationship Between Optimal CO2 Emission and Optimal Cost of the RC Frames

2020 ◽  
Author(s):  
Lida Mottaghi ◽  
Ramezan Ali Izadifard ◽  
Ali Kaveh
Keyword(s):  
Reinforced Concrete ◽  
Co2 Emissions ◽  
Carbon Dioxide Emissions ◽  
Reinforced Concrete Frame ◽  
Optimal Cost ◽  
Concrete Frame ◽  
Rc Frames ◽  
Greenhouse Gases Emissions ◽  
The Cost ◽  
The Relationship

Nowadays, reduction of greenhouse gases emissions from the construction industry is seriously under investigation. The aim of this study is to investigate the various effective factors on the relationship between optimal cost and optimal carbon dioxide emissions of the reinforced concrete structures with nonlinear structural behavior. A four-story reinforced concrete frame is designed for various peak ground accelerations (PGAs) and all ductility classes according to Iran’s seismic resistant design-2800 code, as well as for different concrete classes. The frames are optimally designed according to ACI 318-08 and FEMA codes. The results of optimal designs show that the design of structures with medium and high ductility class produces less cost and CO2 emissions than the low ductility class. On the other hand, the relationship between cost and CO2 emissions shows that in the low ductility class, increasing the percentage of the optimal cost can greatly reduce the amount of CO2 emissions. PGA design has a significant effect on reducing optimal cost and CO2 emissions. Especially in the low ductility class, reducing this parameter can greatly decrease the amount of the objective functions. Also, the use of concrete with low class can reduce the cost and CO2 emissions but the effect of this parameter in the objective is very small.

Sign in / Sign up

Export Citation Format

Share Document