scholarly journals Fragility and robustness analysis of a multistorey RC building

2021 ◽  
Vol 73 (01) ◽  
pp. 27-44
Keyword(s):  
Fragility Curves ◽  
Nonlinear Dynamic Analysis ◽  
Robustness Analysis ◽  
Nonlinear Static Analysis ◽  
Limit States ◽  
Element Loss ◽  
Rc Building ◽  
Frame System ◽  
Nonlinear Static ◽  
Storey Building

The robustness of a reinforced concrete (RC) five-storey building (frame system stiffened by walls) is analysed in the paper. A high ductility class structure is designed in accordance with structural Eurocodes. The response of the structure to eight different scenarios of the ground floor vertical element loss is analysed. Nonlinear Static Analysis (NSA) and Nonlinear Dynamic Analysis (NDA) methods are used for the robustness analysis. Fragility curves of the building are derived from statistical analysis of these results. The values obtained through NSA and NDA, damage limit states of the system, and fragility curves, are compared. The influence of the position of the removed element on robustness of the structure is also analysed.

scholarly journals Assessment of an Existing RC Building before and after Strengthening Using Nonlinear Static Procedure and Incremental Dynamic Analysis

2010 ◽  
Vol 17 (4-5) ◽  
pp. 619-629 ◽  
Author(s):  
Amir A. Hedayat ◽  
Hakan Yalciner
Keyword(s):  
Structural Damage ◽  
Fragility Curves ◽  
Performance Level ◽  
Seismic Zone ◽  
Existing Buildings ◽  
Limit States ◽  
Rc Building ◽  
Nonlinear Static ◽  
Fema 356 ◽  
Strengthening Method

Inadequate attention during design and construction of some of reinforced concrete (RC) buildings in Cyprus has raised questions about the performance level of these existing buildings under future earthquakes. This study aimed to assess the seismic structural response of a four story existing RC building. For this purpose, first, the weak structural elements (e.g.\ the not safety column-beam joints and weak columns) were detected using linear static procedure (LSP) analyses on the basis of Turkish earthquake code. Then, two different strengthening methods were examined. In the first method which is common in Cyprus, the existing building was strengthened based on LSP, using column jacketing to satisfy seismic code requirements to remove the weak elements. The second strengthening method was carried out using nonlinear static procedures (NSP) to achieve the basic safety objective (BSO) performance level described in FEMA 356. For existing and both strengthened structures, pushover curves were obtained and following FEMA 356, performance points were calculated and compared. The seismic responses of existing and strengthened buildings were also assessed using incremental dynamic analyses (IDA). Nonlinear dynamic time history analyses have been performed by using SDOF models of these buildings under action of different scales of 20 ground motion records. Then IDA curves for each earthquake have been constructed. Limit – states at each performance level have been defined and summarizing the multi – record IDA curves, 16%, 50% and 84% fractile curves were obtained. Since selected structure represents common existing buildings in Cyprus, probabilistic structural damage estimation fragility curves were also obtained in terms of peak ground acceleration (PGA) for each considered performance level. Results showed that the strengthening method based on the NSP to satisfy the BSO requirements is much more effective than the one based on the LSP to improve the building performance and to reduce the probability of exceeding of limit states IO, LS and CP at any seismic zone.

Seismic Performance Evaluation of Liquid Storage Tanks Using Nonlinear Static Procedures

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Konstantinos Bakalis ◽  
Athanasia K. Kazantzi ◽  
Dimitrios Vamvatsikos ◽  
Michalis Fragiadakis
Keyword(s):  
Seismic Performance ◽  
Failure Modes ◽  
Fragility Curves ◽  
Nonlinear Static Analysis ◽  
Elastic Response ◽  
Storage Tanks ◽  
Limit States ◽  
Modes Of Failure ◽  
Liquid Storage ◽  
Nonlinear Static

A simplified approach is presented for the seismic performance assessment of liquid storage tanks. The proposed methodology relies on a nonlinear static analysis, in conjunction with suitable “strength ratio-ductility-period” relationships, to derive the associated structural demand for the desired range of seismic intensities. In the absence of available relationships that are deemed fit to represent the nonlinear-elastic response of liquid storage tanks, several incremental dynamic analyses are performed for variable post-yield hardening ratios and periods in order to form a set of data that enables the fitting of the response. Following the identification of common modes of failure such as elephant's foot buckling (EFB), base plate plastic rotation, and sloshing wave damage, the aforementioned relationships are employed to derive the 16%, 50%, and 84% percentiles for each of the respective response parameters. Fragility curves are extracted for the considered failure modes, taking special care to appropriately quantify both the median and the dispersion of capacity and demand. A comparison with the corresponding results of incremental dynamic analysis (IDA) reveals that the pushover approach offers a reasonable agreement for the majority of failure modes and limit states considered.

scholarly journals Evaluation of p-delta effect in structural seismic response

2018 ◽  
Vol 162 ◽  
pp. 04019 ◽  
Author(s):  
Sardasht Sardar ◽  
Ako Hama
Keyword(s):  
Seismic Response ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Steel Structure ◽  
Nonlinear Static Analysis ◽  
Structural Behavior ◽  
Finite Element Software ◽  
History Analysis ◽  
Nonlinear Static

Numerous recent studies have assessed the effect of P-Delta on the structures. This paper investigates the effect of P-Delta in seismic response of structures with different heights. For indicating the effect of P-Delta, nonlinear static analysis (pushover analysis) and nonlinear dynamic analysis (Time history analysis) were conducted by using finite element software. The results showing that the P-Delta has a significant impact on the structural behavior mainly on the peak amplitude of building when the height of the structures increased. In addition, comparison has been made between concrete and steel structure.

Applications of Capacity Spectrum Method for Buildings With Metallic Yielding Dampers

2005 ◽  
Author(s):  
Bo-Jen Chen ◽  
C. S. Tsai ◽  
L. L. Chung ◽  
Tsu-Cheng Chiang
Keyword(s):  
Static Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Iteration Procedure ◽  
Nonlinear Static Analysis ◽  
Severe Damage ◽  
Capacity Spectrum Method ◽  
Spectrum Method ◽  
Capacity Spectrum ◽  
Earthquake Resistant ◽  
Nonlinear Static

The 921 Chi-Chi Earthquake was one of the most destructive earthquakes in Taiwan in the twentieth century. The earthquake caused severe damage or collapse to the residential and public structures. It is a sensible choice to utilize the metallic yielding dampers for retrofitting damaged structures and to enhance earthquake-resistant capacity of new structures. In this paper, in order to facilitate the designs of the metallic yielding dampers, an improved nonlinear static analysis iteration procedure based on the capacity spectrum method for buildings with metallic yielding dampers has been proposed. The numerical results of the buildings with the metallic yielding dampers through the nonlinear static analysis iteration procedure and the nonlinear dynamic analysis have been obtained, compared and verified in this study. Moreover, it is also illustrated that the proposed nonlinear static analysis iteration procedure based on the capacity spectrum method for structures with metallic yielding dampers can fairly predict the seismic responses of the buildings with metallic yielding dampers during the earthquakes.

Effect of damage limit states on the seismic fragility of reinforced concrete frame-shear wall buildings

2021 ◽  
Vol 14 (9) ◽  
pp. 57-68
Author(s):  
Durga Mibang ◽  
Satyabrata Choudhury
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Analysis ◽  
Seismic Vulnerability ◽  
Design Method ◽  
Fragility Curves ◽  
Nonlinear Dynamic Analysis ◽  
Soil Condition ◽  
Shear Wall ◽  
Reinforced Concrete Frame ◽  
Limit States

Assessment of the seismic vulnerability of frame-shear wall buildings can be performed by non-linear dynamic analysis and it needs detailed analytical modeling, structural performance measures and various earthquake intensities. The codal based design method can hardly be used for designing buildings of pre-defined target objectives whereas the Unified performance-based design (UPBD) method can be designed for buildings of pre-defined target objectives. In the current study, the UPBD method for frame-shear wall buildings has been applied for different performance levels (PL) i.e. Immediate occupancy (IO), Life safety (LS) and Collapse prevention (CP) with 1%, 2% and 3% drift in both the directions of the buildings. The nonlinear dynamic analysis of the reinforced concrete (RC) frame-shear wall buildings is performed considering spectrum compatible ground motions (SCGM) as per EC-8 demand spectrum at 0.45g level and type B soil condition. Vulnerability assessment of the frame-shear wall buildings is conducted by generating fragility curves and the probability failure of structure is checked based on different configurations and damage limit states of the structure. Finally, the outcome of the work gives a proper idea of the nonlinear behavior of the dual system so that optimum design could be acquired for achieving higher safety aspects.

Nonlinear Static Analysis for Progressive Collapse Potential of RC Building

2011 ◽  
Vol 94-96 ◽  
pp. 146-152 ◽  
Author(s):  
Tie Cheng Wang ◽  
Zhi Ping Li
Keyword(s):  
Static Analysis ◽  
Progressive Failure ◽  
Progressive Collapse ◽  
Frame Structure ◽  
Nonlinear Static Analysis ◽  
Collapse Potential ◽  
Concrete Frame ◽  
Rc Building ◽  
Edge Span ◽  
Nonlinear Static

In this study, the progressive collapse potential of a 10-storey concrete frame structure was investigated using nonlinear static analysis. 15 different cases were considered and their performances were compared with each other. From the nonlinear static analysis results, most of longitudinal beams in upper floors and slabs above the failure column would collapse as the results of removing an exterior column, no beams and slabs would collapse when an interior column at ground floor was removed, and only the short-span beams in superstructure would collapse when an interior column in upper floors was removed. Tie force reinforcement along floors and beams of edge span can be used to avoid the progressive failure of floors, after failure of particular column.

scholarly journals Seismic Assessment via EC8 of Modern Heritage Structures

2016 ◽  
pp. 1002-1021
Author(s):  
Gerardo M. Verderame ◽  
Flavia De Luca ◽  
Gaetano Manfredi
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Models ◽  
Fragility Curves ◽  
Seismic Assessment ◽  
Eurocode 8 ◽  
Dynamic Identification ◽  
Limit States ◽  
Rc Building ◽  
Nonlinear Dynamic Analyses ◽  
Modal Dynamic Identification

Given the interest earned recently by modern heritage structures, seismic assessment criteria of Eurocode 8, for ordinary reinforced concrete structures, are applied to a modern heritage RC building. The case study, the Tower of the Nations in Naples, allows a discussion on knowledge approaches, analysis methodologies and modeling choices that can be considered. Modal dynamic identification, in situ inspections, and testing provided the necessary knowledge of the structure. Linear and nonlinear models of the structure are built up accounting for tuff infills' stiffness and strength contribution. Numerical modal properties are compared with those obtained through dynamic identification. Lumped plasticity model for reinforced concrete elements and equivalent strut macro models for tuff and concrete infills are employed for the nonlinear model of the structure. Seismic assessment through nonlinear dynamic analyses is carried out for two Limit States. Finally, fragility curves through cloud analysis are obtained for the different limit states considered.

Improvement of progressive collapse resistance potential of semi-rigid jointed steel frames through bracings

2016 ◽  
Vol 7 (4) ◽  
pp. 518-546
Author(s):  
Milan Bandyopadhyay ◽  
Atul Krishna Banik
Keyword(s):  
Static Analysis ◽  
Progressive Collapse ◽  
Steel Frames ◽  
Nonlinear Dynamic Analysis ◽  
Nonlinear Static Analysis ◽  
Braced Frame ◽  
Collapse Resistance ◽  
Column Removal ◽  
Rigid Frames ◽  
Nonlinear Static

Progressive collapse studies of both unbraced and braced semi-rigid jointed steel frames have been carried out to evaluate the contribution of bracings in improving progressive collapse resistance potential. Numerical models of 10-story frames with different types of semi-rigid connections have been developed using SAP2000. Progressive collapse potential of semi-rigid frames is first investigated without bracings. Bracings are then included in a systematic manner, and response of the braced frame is compared with that of unbraced frame to evaluate the contribution of bracings. Two different arrangements of bracings, that is, bay-wise and floor-wise arrangements, are considered to find out a preferred arrangement of bracings. Parametric studies include eight column removal conditions at center and corner locations of different floors. Development of catenary action has also been considered as it gives additional resistance, especially to braced frame. Apart from nonlinear static analysis, effects of bracings are evaluated also through nonlinear dynamic analysis and the responses of the frames in nonlinear dynamic analysis are compared with those of nonlinear static analysis. From the study, it is found that provision of bracings significantly improves the progressive collapse resistance potential of the semi-rigid frames under different column removal conditions. Floor-wise arrangement of bracings is much effective as compared to bay-wise arrangement.

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