Seismic Vulnerability Analysis of Reinforced Concrete Frames with Mild Steel Dampers

2011 ◽  
Vol 368-373 ◽  
pp. 1526-1530 ◽  
Author(s):  
Jian Zhu ◽  
Ping Tan
Keyword(s):  
Reinforced Concrete ◽  
Mild Steel ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Time History ◽  
Concrete Frames ◽  
Rc Frames ◽  
History Analysis ◽  
Reduction Effect

This study focus on derivation of such fragility curves using conventional old reinforced concrete (RC) frames with Mild Steel Damper (MSD) of flexural energy dissipation braces. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. Weak position was be pointed out, The result reveal that excellent reduction effect for structure of MSD is favorable and obvious under major earthquake.

Seismic Vulnerability Analysis of Mid-Story Isolation and Reduction Structures Based Stochastic Vibration

2011 ◽  
Vol 243-249 ◽  
pp. 3988-3991 ◽  
Author(s):  
Pei Ju Chang ◽  
Jian Zhu
Keyword(s):  
Ground Motion ◽  
Random Sample ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Good Effect ◽  
History Analysis ◽  
Reduction Effect

This study focus on derivation of such fragility curves using classic mid-story isolation and reduction structures (MIRS) in China metropolis. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. The result reveal that good effect for superstructure and reduction effect for substructure of MIRS is favorable and obvious under major earthquake, Weak position of MIRS was be pointed out and fragility curves of typical MIRS of China was obtained finally.

Stochastic Vibration-Based Fragility Analysis of Middle-Story RC Frames

2011 ◽  
Vol 204-210 ◽  
pp. 1235-1238
Author(s):  
Jian Zhu ◽  
Ping Tan
Keyword(s):  
Fragility Curves ◽  
Response Spectrum ◽  
Time History ◽  
Seismic Intensity ◽  
Western China ◽  
Fragility Analysis ◽  
Design Practice ◽  
Rc Frames ◽  
History Analysis ◽  
Set Up

A lot of reinforced concrete (RC) frames have being collapsed during Si Chuan Earthquake (SCE) in western China May 12th.2008, at the same time others have being injured on several levers. In recent years how to evaluate reliability and fragility of the buildings and search reasonable design practice of seismic strengthening of these buildings is urgent mission. One goal of fragility analysis is set up relation between vulnerability and seismic intensity. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. In the end structural weak position also be pointed as valuable consultation for diagnose these buildings and fragility curves of typical middle-storey RC frames of China was obtained finally.

Metaheuristic Optimization of Reinforced Concrete Frames

2020 ◽  
pp. 141-160
Keyword(s):  
Reinforced Concrete ◽  
Optimum Design ◽  
Harmony Search ◽  
Time History ◽  
Rc Frame ◽  
Concrete Frames ◽  
Design Constraints ◽  
Rc Frames ◽  
History Analysis ◽  
Internal Forces

In this chapter, an optimum design methodology for reinforced concrete (RC) frames are presented. In the optimum design of frames, both beams and columns are optimized. In addition to that, internal forces can be modified according to rigidity of members for statically indetermined frames. In the presented methodology, the optimization of RC frame is done according to dynamic seismic loads and the design is done according to time-history analysis. As a metaheuristic algorithm, a modified harmony search is used, and the design constraints are provided according to ACI 318: Building code requirements for structural concrete. The optimum results of two span-two story symmetric RC frames and three span-three story RC frame are presented.

Study on Seismic Performance of Reinforced Concrete Masonry High-Rise Building

2012 ◽  
Vol 166-169 ◽  
pp. 2164-2170
Author(s):  
Xu Jie Sun ◽  
Hou Zhang ◽  
Da Gang Lu ◽  
Feng Lai Wang
Keyword(s):  
Reinforced Concrete ◽  
Response Spectrum ◽  
Pushover Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Masonry Building ◽  
Analysis Method ◽  
Concrete Masonry ◽  
History Analysis ◽  
Earthquake Action

The design process of the 100 m high reinforced concrete masonry building in China was firstly presented, deformation check calculation under earthquake action by mode-superposition response spectrum method and time-history analysis method were detailed and deformation under wind load was also checked. Then elastic-plastic deformation under earthquake action was checked by time-history analysis method and pushover analysis method with both under uniform load and reverse triangle load. The conclusion is construct 100 m high office building built in Fortification intensity 6 by reinforced concrete masonry is feasible. Then the building was redesigned as built in fortification 7, the same check was performed as that have been done in fortification 6, it is feasible too.

Seismic Fragility Analysis of Mid-Story Isolation and Reduction Structures Based Two Directions

2013 ◽  
Vol 739 ◽  
pp. 309-313 ◽  
Author(s):  
Pei Ju Chang
Keyword(s):  
Fragility Curves ◽  
Response Spectrum ◽  
Time History ◽  
Longitudinal Axis ◽  
Seismic Intensity ◽  
Seismic Fragility ◽  
Infill Wall ◽  
Intensity Index ◽  
History Analysis ◽  
Masonry Infill Wall

This study focus on derivation of such fragility curves using classic mid-story isolation and reduction structures (MIRS) in China metropolis. This study focus on derivation of such fragility curves using conventional industrial frames with masonry infill wall. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. MIRS seismic capability of longitudinal and transversal orientation is different. Stochastic damage scatter diagrams based different seismic intensity index are obtained. Seismic fragility of longitudinal axis (Y axis) is larger than transversal axis (X axis) of frames under major earthquake obviously.

EFFECTS OF RANDOMLY DISTRIBUTED INFILL ON COLUMNS OF REINFORCED CONCRETE FRAMES WITH SOFT GROUND STOREY

2010 ◽  
Vol 10 (03) ◽  
pp. 555-569 ◽  
Author(s):  
SHAHRIAR QUAYYUM ◽  
ISLAM MOHAMMAD NAZMUL ◽  
MOST. MAHBUBA IASMIN ◽  
KHAN MAHMUD AMANAT
Keyword(s):  
Reinforced Concrete ◽  
Response Spectrum ◽  
Base Shear ◽  
Concrete Frames ◽  
Natural Period ◽  
Rc Frames ◽  
Axial Forces ◽  
Open Ground ◽  
Seismic Loadings ◽  
Structural Responses

Reinforced concrete (RC) frames with an open ground floor and various infill distributions have been analyzed for seismic loadings by the finite element method. The infills have been modeled by diagonal struts. Focus is placed on the effects of infill distribution on various structural responses, including (i) the lateral deflection, (ii) the column axial forces, (iii) the column bending moments, (iv) the base shear, and (v) the natural period of the frame. The equivalent static force method (ESFM) and response spectrum method (RSM) for linear structures have been applied, and the results obtained have been compared. It was found that the structural responses do not change appreciably by the ESFM analysis for random infill distributions, while they increase noticeably in the RSM analysis. This manifests the inadequacy of using the ESFM for general purposes, for which modifications were proposed in this paper for the design of RC columns. As the natural period of the RC frame converges with the code equations only for higher amounts of infill, it is necessary to incorporate the amount and distribution of infill in the dynamic analysis of RC frames.

scholarly journals Effect of Masonry Infill Constitutive Law on the Global Response of Infilled RC Buildings

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 57
Author(s):  
Marco Gaetani d’Aragona ◽  
Maria Polese ◽  
Andrea Prota
Keyword(s):  
Reinforced Concrete ◽  
Fragility Curves ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Time History ◽  
Element Model ◽  
Constitutive Law ◽  
Concrete Frames ◽  
Reinforced Concrete Frames ◽  
Mediterranean Countries

Masonry-infilled reinforced concrete frames represent a very common construction typology across the Mediterranean countries. The presence of infills substantially modifies the global seismic performances of buildings in terms of strength, stiffness, and energy dissipation. Although several research studies focused on the overall performances of infilled reinforced concrete frames, the modeling of infill panels remains an open issue due to the complex interaction between the infill and the frame and the uncertainties involved in the definition of the problem. In the present paper, an existing masonry-infilled RC frame designed according to obsolete seismic codes is chosen as a case study. A refined three-dimensional finite element model is built for performing nonlinear static and time-history analyses in order to investigate some significant aspects related to the modeling of infills. In particular, it is investigated the effect of different infill constitutive models on the seismic performance of infilled RC building expressed in terms of engineering demand parameters such as interstory drift ratios and peak floor accelerations, and on the generation of damage fragility curves.

scholarly journals Effect of Buoyancy Loads on the Tsunami Fragility of Reinforced Concrete Frames Including Consideration of Blow-out Slabs

2021 ◽  
Author(s):  
Marta Del Zoppo ◽  
Tiziana Rossetto ◽  
Marco Di Ludovico ◽  
Andrea Prota
Keyword(s):  
Reinforced Concrete ◽  
Damage Evolution ◽  
Structural Damage ◽  
Shear Failure ◽  
Fragility Curves ◽  
Indirect Costs ◽  
Concrete Frames ◽  
Rc Frames ◽  
Tsunami Fragility

Abstract Currently available performance-based methodologies for assessing the fragility of structures subjected to tsunami neglect the effects of tsunami-induced vertical loads due to internal buoyancy. This paper adopts a generalized methodology for the performance assessment of structures that integrates the effects of buoyancy loads on slabs during a tsunami inundation. The methodology is applied in the fragility assessment of three case-study frames (low, mid and high-rise), representative of existing masonry-infilled reinforced concrete (RC) buildings typical of Mediterranean region. The paper shows the effect of modelling buoyancy loads on damage evolution, structural performance and fragility curves associated with different structural damage mechanisms for RC frames with breakaway infill walls including consideration of blow-out slabs. The outcomes attest that the predominant failure mechanism of selected case-study is the brittle shear failure of seaward columns, which is slightly affected by buoyancy loads. When brittle failure is avoided, buoyancy loads significantly affect the damage evolution during a tsunami, especially in the case of structures with blow-out slabs. The rate of occurrence of slabs uplift failure increases with the number of stories of the building but only slightly affects the fragility curves of investigated structures. However, it can significantly increase their vulnerability, affecting both direct and indirect costs deriving from the repair of the damaged interior slabs.

Development of Fragility Curves for Multi-Span RC Bridges using Generalized Pushover Analysis

2019 ◽  
Author(s):  
Camilo Perdomo ◽  
Ricardo Monteiro ◽  
Halûk Sucuoğlu
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Pushover Analysis ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Engineering Practice ◽  
Nonlinear Analyses ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Existing Bridges

<p>Over the past few decades, fragility curves became a powerful tool for the seismic vulnerability assessment of structures. There are several available analytical procedures for calculating fragility curves, using both static and dynamic nonlinear analyses. In this study, a nonlinear static method, based on Generalized Pushover Analysis (GPA), is implemented for the development of analytical fragility curves of reinforced concrete (RC) bridges. The relative accuracy of the GPA algorithm, when applied to a large number of existing bridges, is evaluated through the comparison with the results from Nonlinear Time History Analysis (NTHA). Results indicate that GPA provides a good estimation of the fragility curves with respect to NTHA. The added computational demand of the GPA algorithm in terms of the number of analyses pays off in terms of accuracy while keeping the simplicity of a non-adaptive conventional pushover algorithm, which is desirable in engineering practice.</p>

Seismic Fragility Analysis of RC Industrial Frames Based Stochastic Vibration

2013 ◽  
Vol 717 ◽  
pp. 301-305 ◽  
Author(s):  
Pei Ju Chang ◽  
Jian Zhu
Keyword(s):  
Fragility Curves ◽  
Response Spectrum ◽  
Time History ◽  
Longitudinal Axis ◽  
Seismic Intensity ◽  
Seismic Fragility ◽  
Infill Wall ◽  
Intensity Index ◽  
History Analysis ◽  
Masonry Infill Wall

This study focus on derivation of such fragility curves using conventional industrial frames with masonry infill wall. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. Industrial structural seismic capability of longitudinal and transversal orientation is different. Stochastic damage scatter diagrams based different seismic intensity index are obtained. Seismic fragility of longitudinal axis (X axis) is larger than transversal axis (Y axis) of frames under major earthquake obviously.

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