Damage Variation in Highway Bridge Piers for Rehabilitation with Different Reinforced Options

2013 ◽  
Vol 569-570 ◽  
pp. 254-261
Author(s):  
Consuelo M. Gómez-Soberón ◽  
Bertha Olmos-Navarrete ◽  
Manuel Jara-Díaz ◽  
José Manuel Jara-Guerrero
Keyword(s):  
Fragility Curves ◽  
Damage Index ◽  
Bridge Piers ◽  
Highway Bridge ◽  
Seismic Action ◽  
Damage Level ◽  
Degree Of Protection ◽  
Seismic Scenarios ◽  
Earthquake Zone ◽  
High Degree

Bridges are considered as vital components that require a high degree of protection to guarantee their functionality, even after significant earthquakes. So, the damage evaluation of current conditions of these structures is considered a necessary tool for inspection, maintenance and rehabilitation. Seismic fragility curves of a common highway bridge structure, with simple-supported girders, for different seismic scenarios, are evaluated in this paper. The selected bridge is a RC system with rectangular piers, forming a frame substructure; the bridge piers reinforcement is designed using steel jackets. Damage fragility curves are again evaluated for the reinforced system and compared with the initial condition; for that, a non-linear analyses with Ruaumoko program are accomplished, using a Takeda constitutive model and the damage index proposed by Parket al. As an external seismic action, artificial accelerograms are obtained based on signals registered in the most hazardous earthquake zone of Mexico. The probability changes of a certain damage level are verified for the obtained results.

scholarly journals PREDICTION OF ULTRALOW CYCLE FATIGUE DAMAGE OF THIN-WALLED STEEL BRIDGE PIERS

2021 ◽  
Keyword(s):  
Cyclic Loading ◽  
Base Metal ◽  
Structural Parameters ◽  
Damage Index ◽  
Bridge Piers ◽  
Steel Bridge ◽  
Cycle Fatigue ◽  
Damage Level ◽  
Deposited Metal ◽  
Thin Walled

Ultralow cycle fatigue (ULCF) failure was first observed on steel bridge piers in the Kobe earthquake, and the ultimate strength and ductility evaluation formulas of thin-walled steel bridge piers were established. In this study, parametric analysis of steel piers was carried out to study the influence of the structural parameters on the ULCF damage evolution. The evolution of the ULCF damage of the base metal, the deposited metal, and the heat-affected zones was studied based on two types of steel piers with hollow box and pipe sections. Then, practical formulas to predict the ULCF damage level of steel piers under cyclic loading were proposed. Finally, the proposed formulas were validated by comparisons with the experimental results. The results show that the heat-affected zone is more vulnerable to ULCF failure than the base metal and the deposited metal. Moreover, the practical formulas to predict the ULCF damage index of the steel piers under cyclic loading were proposed, and the formulas effectively predicted the ULCF crack of the steel piers.

Post-Seismic Damage Assessment of a Historical Masonry Building: The Case Study of a School in Teramo

2017 ◽  
Vol 747 ◽  
pp. 620-627 ◽  
Author(s):  
Silvia Colonna ◽  
Stefania Imperatore ◽  
Maria Zucconi ◽  
Barbara Ferracuti
Keyword(s):  
Central Italy ◽  
Damage Index ◽  
Vulnerability Index ◽  
Seismic Damage ◽  
Seismic Intensity ◽  
Masonry Building ◽  
Seismic Action ◽  
Damage Level ◽  
Historical Masonry

The historical masonry buildings are characterised by a great vulnerability regard the seismic action, as the recent events occurred in Central Italy have highlighted. During the seismic emergency the authors, in collaboration with the Civil Protection Department as part of the ReLUIS activities, have carried out usability inspections, analysing also the case study described in this paper. The structure, a school in Teramo, was already affected by previously seismic damages and it has been highly involved by the seismic events abovementioned. In this work the results of first inspection, reported in the AeDES form, and a more accurate visual inspection are presented in terms of detection of the crack patterns and evaluation of the seismic damages index. Moreover the vulnerability index has been calculated according to the GNDT 2° level method. The vulnerability index is finally used to calculate the damage index expected for the seismic intensity registered during the seismic event of October 30, 2016, and compared with the observed post-seismic damage level.

scholarly journals Fragility estimation for global building classes using analysis of the Cambridge earthquake damage database (CEQID)

2021 ◽  
Author(s):  
Robin Spence ◽  
Sandra Martínez-Cuevas ◽  
Hannah Baker
Keyword(s):  
Fragility Curves ◽  
Resistance Index ◽  
Earthquake Damage ◽  
Ground Acceleration ◽  
Damage Level ◽  
Ground Motion Parameter ◽  
Geographical Regions ◽  
Concrete Building ◽  
Damage Data ◽  
Regional Comparisons

AbstractThis paper describes CEQID, a database of earthquake damage and casualty data assembled since the 1980s based on post-earthquake damage surveys conducted by a range of research groups. Following 2017–2019 updates, the database contains damage data for more than five million individual buildings in over 1000 survey locations following 79 severely damaging earthquakes worldwide. The building damage data for five broadly defined masonry and reinforced concrete building classes has been assembled and a uniform set of six damage levels assigned. Using estimated peak ground acceleration (PGA) for each survey location based on USGS Shakemap data, a set of lognormal fragility curves has been developed to estimate the probability of exceedance of each damage level for each class, and separate fragility curves for each of five geographical regions are presented. A revised set of fragility curves has also been prepared in which the bias in the curve resulting from the uncertainty in the ground motion parameter has been removed. The uncertainty in the fragility curves is evaluated and discussed and the curves are compared with those from other studies. A resistance index for each class of building is developed and cross-regional comparisons using this resistance index are presented.

scholarly journals New tsunami damage functions developed in the framework of SCHEMA project: application to European-Mediterranean coasts

2011 ◽  
Vol 11 (10) ◽  
pp. 2835-2846 ◽  
Author(s):  
N. Valencia ◽  
A. Gardi ◽  
A. Gauraz ◽  
F. Leone ◽  
R. Guillande
Keyword(s):  
Fragility Curves ◽  
Construction Material ◽  
Maximum Flow ◽  
Indian Ocean Tsunami ◽  
Cumulative Probability ◽  
Flow Depth ◽  
Damage Functions ◽  
Damage Level ◽  
Tsunami Damage ◽  
Mediterranean Areas

Abstract. In the framework of the European SCenarios for tsunami Hazard-induced Emergencies MAnagement (SCHEMA) project (www.schemaproject.org), we empirically developed new tsunami damage functions to be used for quantifying the potential tsunami damage to buildings along European-Mediterranean coasts. Since no sufficient post-tsunami observations exist in the Mediterranean areas, we based our work on data collected by several authors in Banda Aceh (Indonesia) after the 2004 Indian Ocean tsunami. Obviously, special attention has been paid in focusing on Indonesian buildings which present similarities (in structure, construction material, number of storeys) with the building typologies typical of the European-Mediterranean areas. An important part of the work consisted in analyzing, merging, and interpolating the post-disaster observations published by three independent teams in order to obtain the spatial distribution of flow depths necessary to link the flow-depth hazard parameter to the damage level observed on buildings. Then we developed fragility curves (showing the cumulative probability to have, for each flow depth, a damage level equal-to or greater-than a given threshold) and damage curves (giving the expected damage level) for different classes of buildings. It appears that damage curves based on the weighted mean damage level and the maximum flow depth are the most appropriate for producing, under GIS, expected damage maps for different tsunami scenarios.

scholarly journals Numerical Analysis of an Earthen Masonry Structure Subjected to Blast Loading

CivilEng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 969-985
Author(s):  
Demiana Tse ◽  
João M. Pereira ◽  
Paulo B. Lourenço
Keyword(s):  
Damage Index ◽  
Damage Threshold ◽  
Impulsive Loading ◽  
World Heritage Site ◽  
Unesco World Heritage ◽  
Damage Level ◽  
Heritage Site ◽  
Pressure Profiles ◽  
Unesco World Heritage Site ◽  
Explicit Dynamic

Historic monuments and construction capture the knowledge of civilizations of the past and are a source of pride for people of the present. Over the centuries, these buildings have been at risk from natural and man-made causes. The Alhambra, a UNESCO World Heritage Site in Granada, Spain, is one of such places. This paper aims to evaluate the structural performance of the Torre de la Vela, a tower in the Alhambra, under blast loads. The loads were based on historical records of barrels of gunpowder and were modeled as simplified pressure profiles using existing empirical equations. The effect of impulsive loading on the material properties was accounted for using dynamic increase factors, determined experimentally by previous authors. The model was created using finite element methods (FEM) and the problem was solved using explicit dynamic analysis available in Abaqus/Explicit. Using the failure volume damage index, a blast load applied outside and inside of the building would create a low damage level, which should be treated with caution given the occurrence of localized damage. The removal of elements exceeding a given damage threshold led to more visible damage patterns than the Concrete Tension Damage option in Abaqus.

scholarly journals Effectiveness of COVID-19 vaccines against delta variant (B.1.617.2): A meta-analysis

2021 ◽  
Author(s):  
Rashidul Alam Mahumud ◽  
Mohammad Afshar Ali ◽  
Satyajit Kundu ◽  
Md Ashfikur Rahman ◽  
Joseph Kihika Kamara ◽  
...  
Keyword(s):  
Risk Ratio ◽  
Vaccine Coverage ◽  
Meta Analysis ◽  
Random Effect ◽  
Herd Immunity ◽  
Case Control Studies ◽  
Health Crisis ◽  
Degree Of Protection ◽  
Study Designs ◽  
High Degree

Abstract ObjectivesThe highly transmissible COVID-19 delta variant (DV) has contributed to the surge in cases and has now been exacerbated the worldwide public health crisis. Several COVID-19 vaccines play a significant role in a high degree of protection against DV. The primary purpose of this meta-analysis is to estimate the pooled effectiveness of the COVID-19 vaccines against DV in terms of risk ratio (RR) among fully vaccinated, compared to unvaccinated populations.MethodsWe carried out a systematic review with meta-analysis of original studies focused on COVID-19 vaccines effectiveness of COVID-19 vaccines against B.1.617.2 clinical perspective among fully COVID-19 vaccinated populations, compared to placebo (unvaccinated populations), published before September 30, 2021. Eleven studies containing data of 17.2 million participants were identified and included in our study. Pooled estimates of COVID-19 vaccines effectiveness (i.e., risk ratio, RR) against delta variant with 95% confidence intervals were assessed using random-effect models. Publication bias was assessed using Egger's regression test and funnel plot to investigate potential sources of heterogeneity and identify any differences in study design.ResultsA total population of 17.2 million (17,200,341 peoples) were screened for the COVID-19 vaccines' effectiveness against delta variant. We found 61.13% of study population were fully vaccinated with 2-dose of COVID-19 vaccines. Weighted pooled incidence of COVID-19 infection was more than double (20.07%) among unvaccinated populations, compared to the fully vaccinated population (8.16%). Overall, the effectiveness of COVID-19 vaccine against DV was 85% (RR = 0.15, 95% CI: 0.07-0.31). The effectiveness of COVID-19 vaccines varied slidably by study designs, 87% (RR = 0.13, 95% CI: 0.06-0.30) and 84% (RR = 0.16, 95% CI:0.02, 1.64) for cohort and case-control studies, respectively. ConclusionEffectiveness COVID-19 vaccines were noted to offer higher protection against delta variant among populations who received two vaccine doses compared with unvaccinated populations. This finding would help efforts to maximise vaccine coverage (i.e., at least 60 to 70% of the population) with two doses among vulnerable populations to have herd immunity to breat the chain of transmission and gain greater overall population protection more rapidly.

Effectiveness of Vancomycin Against Gaffkemia, the Bacterial Disease of Lobsters (Genus Homarus)

1974 ◽  
Vol 31 (12) ◽  
pp. 1873-1879 ◽  
Author(s):  
James E. Stewart ◽  
B. Arie
Keyword(s):  
Body Weight ◽  
Penicillin G ◽  
Bacterial Disease ◽  
Infection Rates ◽  
Complete Protection ◽  
Degree Of Protection ◽  
Aerococcus Viridans ◽  
High Degree ◽  
Established Infection

The antibiotics vancomycin, penicillin G, novobiocin, and oxytetracycline were examined for in vivo effectiveness against gaffkemia, the fatal bacterial infection of lobsters (genus Homarus) caused by Aerococcus viridans (var.) homari (formerly Gaffkya homari). Only vancomycin was truly effective against an established infection and then only when given at high levels (25 mg/kg lobster body weight) in the early stages of infection, prior to development of hemolymph bacterial numbers in excess of 3 × 104/ml or coincident hepatopancreatic bacterial levels of 1 × 107/g. Even massive cumulative doses (500 mg vancomycin/kg body weight), when given after establishment of maximum bacterial numbers, failed to impede the infection. Rates for the clearance of vancomycin from lobsters, established by using three different concentrations (25, 10, and 5 mg/kg body weight, respectively), were extremely slow and markedly concentration dependent. Twenty-five milligrams vancomycin/kg body weight injected prior to infection still gave a high degree of protection against challenge with the pathogen 50 days later in lobsters held at 15 C. One milligram vancomycin/kg body weight administered prior to infection gave complete protection against gaffkemia for 15 days after the antibiotic had been administered.

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