Fragility Analysis of 3D Reinforced Concrete Frames Based on Endurance Time Method with Derived Standard Deviation

2017 ◽  
Vol 11 (04) ◽  
pp. 1750011 ◽  
Author(s):  
H. A. Tavazo ◽  
A. Ranjbaran
Keyword(s):  
Standard Deviation ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Fragility Curves ◽  
Computational Cost ◽  
Fragility Analysis ◽  
Easy Access ◽  
Statistical Parameters ◽  
Endurance Time ◽  
Fragility Function

Fragility curves have been developed for seismic vulnerability analysis of structures and can be generated in empirical and analytical forms. To develop analytical fragility curve, the incremental dynamic analysis (IDA) method is considered as an applicable tool for seismic analysis; however, in the cases with high modeling complexity, the computational cost of the IDA method may be very high. Therefore, an alternative method called as endurance time (ET) method can be effectively used for fragility analysis. In this study, a new, accurate and cost effective method has been introduced in order to develop analytical fragility curves based on the ET method. The results reveal that ET-based fragility curves generally agree well with IDA-based fragility curves. In addition, it is revealed that a highly matched fragility function can be fitted on fragility points using ET-based fragility analysis (due to continuity of these points in every 0.01 of IM changes). It is concluded that ET analysis offers convenient and easy access to median and logarithmic standard deviation of IMs and thus fragility function can be produced easily based on these statistical parameters. Furthermore, a new ET-based methodology is presented to consider the previously experienced earthquakes (PEEQs) in generating fragility surfaces.

scholarly journals Dynamic Damage Mechanism and Seismic Fragility Analysis of an Aqueduct Structure

2021 ◽  
Vol 11 (24) ◽  
pp. 11709
Author(s):  
Xinyong Xu ◽  
Xuhui Liu ◽  
Li Jiang ◽  
Mohd Yawar Ali Khan
Keyword(s):  
Ground Motion ◽  
Structural Damage ◽  
Large Scale ◽  
Seismic Analysis ◽  
Fragility Curves ◽  
Limit State ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Exceedance Probability ◽  
Computation Efficiency

The Concrete Damaged Plasticity (CDP) constitutive is introduced to study the dynamic failure mechanism and the law of damage development to the aqueduct structure during the seismic duration using a large-scale aqueduct structure from the South-to-North Water Division Project (SNWDP) as a research object. Incremental dynamic analysis (IDA) and multiple stripe analysis (MSA) seismic fragility methods are introduced. The spectral acceleration is used as the scale of ground motion record intensity measure (IM), and the aqueduct pier top offset ratio quantifies the limit of structural damage measure (DM). The aqueduct structure’s seismic fragility evaluation curves are constructed with indicators of different seismic intensity measures to depict the damage characteristics of aqueduct structures under different seismic intensities through probability. The results show that penetrating damage is most likely to occur on both sides of the pier cap and around the pier shaft in the event of a rare earthquake, followed by the top of the aqueduct body, which requires the greatest care during an earthquake. The results of two fragility analysis methodologies reveal that the fragility curves are very similar. The aqueduct structure’s first limit state level (LS1) is quite steep and near the vertical line, indicating that maintaining the excellent condition without damage in the seismic analysis will be challenging. Except for individual results, the overall fragility results are in good agreement, and the curve change rule is the same. The exceedance probability in the case of any ground motion record IM may be estimated using only two factors when using the MSA approach, and the computation efficiency is higher. The study of seismic fragility analysis methods in this paper can provide a reference for the seismic safety evaluation of aqueducts and similar structures.

scholarly journals Modelling and Characterizing a Concrete Gravity Dam for Fragility Analysis

2019 ◽  
Vol 4 (4) ◽  
pp. 62 ◽  
Author(s):  
Segura Rocio L. ◽  
Bernier Carl ◽  
Durand Capucine ◽  
Patrick Paultre
Keyword(s):  
Earthquake Engineering ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Fragility Analysis ◽  
Past Century ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Eastern Canada ◽  
Safety Guidelines

Most gravity dams have been designed and built during the past century with methods of analysis that are now considered inadequate. In recent decades, knowledge of seismology, structural dynamics and earthquake engineering has greatly evolved, leading to the evaluation of existing dams to ensure public safety. This study proposes a methodology for the proper modelling and characterisation of the uncertainties to assess the seismic vulnerability of a dam-type structure. This study also includes all the required analyses and verifications of the numerical model prior to performing a seismic fragility analysis and generating the corresponding fragility curves. The procedure presented herein also makes it possible to account for the uncertainties associated with the modelling parameters as well as the randomness in the seismic solicitation. The methodology was applied to a case study dam in Eastern Canada, whose vulnerability was assessed against seismic events with characteristics established by the current safety guidelines.

Enhanced Seismic Fragility Analysis of Unanchored Steel Storage Tanks Accounting for Uncertain Modeling Parameters

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci ◽  
Silvia Alessandri
Keyword(s):  
Seismic Vulnerability ◽  
Failure Modes ◽  
Fragility Curves ◽  
Pushover Analysis ◽  
Sampling Procedure ◽  
Fractional Factorial ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Bottom Plate ◽  
Storage Tanks

Catastrophic failure of the above ground steel storage tanks was observed during past earthquakes, which caused serious economic and environmental consequences. Many of the existing tanks were designed in the past with outdated analysis methods and with underestimated seismic loads. Therefore, the evaluation of the seismic vulnerability of these tanks, especially ones located in seismic prone areas, is extremely important. Seismic fragility functions are useful tools to quantify the seismic vulnerability of structures in the framework of probabilistic seismic risk assessment. These functions give the probability that a seismic demand on a given structural component meets or exceeds its capacity. The objective of this study is to examine the seismic vulnerability of an unanchored steel storage tank, considering the uncertainty of modeling parameters that are related to material and geometric properties of the tank. The significance of uncertain modeling parameters is first investigated with a screening study, which is based on nonlinear static pushover analyses of the tank using the abaqus software. In this respect, a fractional factorial design and an analysis of variance (ANOVA) have been adopted. The results indicate that the considered modeling parameters have significant effects on the uplift behavior of the tank. The fragility curves of two critical failure modes, i.e., the buckling of the shell plate and the plastic rotation of the shell-to-bottom plate joint, are then developed based on a simplified model of the tank, where the uplift behavior is correctly modeled from the static pushover analysis. The uncertainty associated with the significant parameters previously identified are considered in the fragility analysis using a sampling procedure to generate statistically significant samples of the model. The relative importance of different treatment levels of the uncertainty on the fragility curves of the tank is assessed and discussed in detail.

Seismic Vulnerability of Reinforced Concrete Building Based on the Development of Fragility Curve: A Case Study

2016 ◽  
Vol 845 ◽  
pp. 252-258 ◽  
Author(s):  
Erlin Wijayanti ◽  
Stefanus Kristiawan ◽  
Edy Purwanto ◽  
Senot Sangadji
Keyword(s):  
Standard Deviation ◽  
Ground Motion ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Pushover Analysis ◽  
Fragility Curve ◽  
Capacity Curves ◽  
Capacity Spectrum ◽  
Damage States ◽  
Spectrum Curve

This study aims to determine the seismic vulnerability of 5th Building of Engineering Faculty, Sebelas Maret University by developing its fragility curves. Fragility curve is a measure of probabilistic seismic performance under various ground motion. The intensity of ground motion adopted in this study is median spectral displacement, , with lognormal standard deviation, βds as uncertainty parameter. The value of lognormal standard deviation is adopted from HAZUS. The parameters of median spectral displacements are identified from the capacity spectrum curve. The capacity curve obtained from non-linear static pushover analysis. Capacity curves can be converted into capacity spectrum to identify the location of the median spectral displacement at various damage states. The obtained fragility curves provide information on the probability of various damage states to occur when certain ground motion level strikes the building under study.

A Kriging-Based Surrogate Model for Seismic Fragility Analysis of Unanchored Storage Tanks

2019 ◽  
Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci ◽  
Daniele Corritore ◽  
Nicola Tondini ◽  
Oreste S. Bursi
Keyword(s):  
Surrogate Model ◽  
Seismic Vulnerability ◽  
Numerical Models ◽  
Fragility Curves ◽  
Computational Cost ◽  
Three Dimensional ◽  
Shaking Table ◽  
Fe Model ◽  
Storage Tanks ◽  
Damage State

Abstract The seismic vulnerability of aboveground steel storage tanks has been dramatically proved during the latest seismic events, which demonstrates the need for reliable numerical models for vulnerability and risk assessments of storage facilities. While for anchored aboveground tanks, simplified models are nowadays available and mostly used for the seismic vulnerability assessment, in the case of unanchored tanks, the scientific community is still working on numerical models capable of reliably predicting the nonlinearity due to uplift and sliding mechanisms. In this paper, a surrogate model based on a Kriging approach is proposed for a case study of an unanchored tank, whose calibration is performed on a three-dimensional finite element (3D FE) model using a reliable design of experiments (DOE) method. The verification of the 3D FE model is also done through a shaking table campaign. The outcomes show the effectiveness of the proposed model to build fragility curves at a low computational cost of the critical damage state of the tank, i.e., the plastic rotation of the shell-to-bottom joint.

scholarly journals Fragility Analysis of Existing Unreinforced Masonry Buildings through a Numerical-based Methodology

2012 ◽  
Vol 6 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Amin Karbassi ◽  
Pierino Lestuzzi
Keyword(s):  
Seismic Vulnerability ◽  
Numerical Models ◽  
Fragility Curves ◽  
Progressive Collapse ◽  
Unreinforced Masonry ◽  
Fragility Analysis ◽  
Stone Masonry ◽  
Masonry Buildings ◽  
Plane Failure ◽  
Element Method

As an approach to the problem of seismic vulnerability evaluation of existing buildings using the predicted vul-nerability method, numerical models can be applied to define fragility curves of typical buildings which represent building classes. These curves can be then combined with the seismic hazard to calculate the seismic risk for a building class (or individual buildings). For some buildings types, mainly the unreinforced masonry structures, such fragility analysis is complicated and time consuming if a Finite Element-based method is used. The FEM model has to represent the structural geometry and relationships between different structural elements through element connectivity. Moreover, the FEM can face major challenges to represent large displacements and separations for progressive collapse simulations. Therefore, the Applied Element Method which combines the advantages of FEM with that of the Discrete Element Method in terms of accurately modelling a deformable continuum of discrete materials is used in this paper to perform the fragility analysis for unreinforced masonry buildings. To this end, a series of nonlinear dynamic analyses using the AEM has been per-formed for two unreinforced masonry buildings (a 6-storey stone masonry and a 4-storey brick masonry) using more than 50 ground motion records. Both in-plane and out-of-plane failure have been considered in the damage analysis. The dis-tribution of the structural responses and inter-storey drifts are used to develop spectral-based fragility curves for the five European Macroseismic Scale damage grades.

SEISMIC VULNERABILITY ASSESSMENT FOR SAN FRANCISCO TEMPLE IN MORELIA, MEXICO

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 207-2016
Author(s):  
Guillermo Martinez ◽  
David Castillo ◽  
José Jara ◽  
Bertha Olmos
Keyword(s):  
San Francisco ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Middle Part ◽  
Seismic Demands ◽  
Modeling And Analysis ◽  
Seismic Records ◽  
Cracking Pattern ◽  
The Temple

This paper presents a first approximation of the seismic vulnerability of a sixteenth century building which is part of the historical center of Morelia, Mexico. The city was declared World Heritage by United Nations Educational, Scientific and Cultural Organization in 1991. The modeling and analysis of the building was carried out using a three-dimensional elastic tetrahedral finite elements model which was subjected to probabilistic seismic demands with recurrences of 500 yrs and 1000 yrs in addition to real seismic records. The model was able to correctly identify cracking pattern in different parts of the temple due to gravitational forces. High seismic vulnerability of the arched window and the walls of the middle part of the bell tower of the temple was indicated by the seismic analysis of the model.

Application of the endurance time methodology on seismic analysis and performance assessment of hydraulic arched tunnels

2021 ◽  
Vol 115 ◽  
pp. 104022
Author(s):  
Benbo Sun ◽  
Mingjiang Deng ◽  
Sherong Zhang ◽  
Chao Wang ◽  
Yang Li ◽  
...  
Keyword(s):  
Performance Assessment ◽  
Seismic Analysis ◽  
Endurance Time ◽  
And Performance

scholarly journals Fragility curves for Italian URM buildings based on a hybrid method

2021 ◽  
Author(s):  
A. Sandoli ◽  
G. P. Lignola ◽  
B. Calderoni ◽  
A. Prota
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Limit State ◽  
Ultimate Limit State ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Behaviour ◽  
Building Stock ◽  
Ground Acceleration ◽  
Damage Scenario

AbstractA hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.

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