Using Collapse Risk Assessments to Inform Seismic Safety Policy for Older Concrete Buildings

2012 ◽  
Vol 28 (4) ◽  
pp. 1495-1521 ◽  
Author(s):  
Abbie B. Liel ◽  
Gregory G. Deierlein
Keyword(s):  
Earthquake Engineering ◽  
Nonlinear Dynamic Analysis ◽  
Concrete Frames ◽  
Seismic Safety ◽  
Building Collapse ◽  
Safety Standards ◽  
Concrete Buildings ◽  
Concrete Frame ◽  
History Of ◽  
The Impact

For many in the engineering community, nonductile concrete buildings are the next priority for seismic safety legislation in California. The history of such policies shows that implementation has been challenged by the high costs of seismic retrofit, opposition from building owners, and difficulty in defining and evaluating seismic safety standards. As a result, seismic legislation for existing buildings has developed in response to major earthquakes, rather than through proactive risk assessment. Advances in performance-based earthquake engineering provide a consistent framework for assessing building collapse risk using nonlinear dynamic analysis. These tools are applied to evaluate the risk of earthquake-induced collapse and fatalities in a representative set of older concrete frames. Results show that nonductile concrete frame buildings are about 35 times more likely to collapse in earthquakes than their modern counterparts. These assessments are used to investigate the impact of policy alternatives for seismic mitigation of nonductile concrete buildings.

scholarly journals Impact of Earthquake Types and Aftershocks on Loss Assessment of Non-Code-Conforming Buildings: Case Study with Victoria, British Columbia

2017 ◽  
Vol 33 (2) ◽  
pp. 551-579 ◽  
Author(s):  
Solomon Tesfamariam ◽  
Katsuichiro Goda
Keyword(s):  
British Columbia ◽  
Reinforced Concrete ◽  
Earthquake Engineering ◽  
Concrete Frames ◽  
Loss Assessment ◽  
Rc Frames ◽  
Annual Probability ◽  
Story Drift ◽  
Hysteretic Characteristics ◽  
The Impact

This paper presents a study on the impact of earthquake types (shallow crustal, deep inslab, and megathrust Cascadia interface earthquakes) and aftershocks on loss assessment of non-code-conforming reinforced concrete (RC) buildings. The loss assessment is formulated within the performance-based earthquake engineering framework. The dependency between the maximum and residual inter-story drift ratios are captured using copulas. Finite-element models that take into account key hysteretic characteristics of non-ductile RC frames were adopted and incremental dynamic analysis is utilized to compute collapse risk. The proposed procedure is applied to a set of 2-, 4-, 8-, and 12-story non-ductile reinforced concrete frames located in Victoria, British Columbia, Canada. From the results, the aftershock showed marked difference for the 2-story building. At annual probability of 10−2–10−3, crustal and inslab events with Mw6.5 to Mw7.5 contributed the most to the loss as these events occur more frequently. At rarer annual probability of 10−3–10−4, the Cascadia event having Mw8.5 to Mw9.0 is predominant and contributed the most to the loss.

International Visions and Goals for the Earthquake Engineering Research Institute

2003 ◽  
Vol 19 (2) ◽  
pp. 221-229
Author(s):  
C. D. Poland ◽  
S. M. Alcocer
Keyword(s):  
Earthquake Engineering ◽  
Seismic Vulnerability ◽  
The United States ◽  
Capital Investments ◽  
Seismic Safety ◽  
Engineering Research ◽  
History Of ◽  
Tools And Techniques ◽  
Collaborative Efforts ◽  
Research Institute

The Earthquake Engineering Research Institute (EERI) has recently added public advocacy for seismic safety to its rich history of facilitating the discussion amongst earthquake scientists and engineers. In recognition of its unique role as the authoritative source for information in the United States, EERI also seeks to partner with other nations to develop information for use worldwide. In 2002, EERI began forming cooperation agreements with organizations in other countries that encourage the exchange of information, collaborative efforts in learning from earthquakes, joint memberships, development of mitigation tools and techniques, and access to seminars, conferences, and technical publications. The ultimate goal of the program is to arrest the growth of seismic vulnerability worldwide and thereby save lives, protect capital investments, and minimize economic impacts.

Earthquake Loss Estimates and Policy Implications for Nonductile Concrete Buildings in Los Angeles

2016 ◽  
Vol 32 (4) ◽  
pp. 1951-1973 ◽  
Author(s):  
Thalia Anagnos ◽  
Mary C. Comerio ◽  
Jonathan P. Stewart
Keyword(s):  
High Risk ◽  
Los Angeles ◽  
Task Force ◽  
Policy Implications ◽  
Seismic Safety ◽  
Collapse Potential ◽  
Concrete Buildings ◽  
Earthquake Loss ◽  
The Impact ◽  
Policy Proposals

The collapse potential of nonductile concrete buildings represents a substantial life safety hazard globally that can be mitigated through carefully crafted policy. Mitigation policy should be approached incrementally by (1) understanding problem scale, (2) screening for low- and high-risk buildings, (3) performing engineering analysis for potentially vulnerable buildings, and (4) retrofit or replacement of high-risk structures. This research addresses initial stages of this sequence for Los Angeles, California. The intent was to investigate approaches for informing mitigation priorities by: characterizing the inventory of approximately 1,500 pre-1976 concrete buildings; estimating risk, including identification of building types that contribute most substantially to the risk; and investigating the impact of retrofit policy alternatives. Loss estimates for scenario events are based on the HAZUS™ Advanced Engineering Building Module. Depending on model assumptions, losses range from $1.8 to $28.5 billion and <50 to 8,300 fatalities. We investigate proposals targeting vulnerable buildings for retrofit as compared to retrofitting all buildings in the inventory. Awareness raised by this research contributed to the formation of the Los Angeles Mayoral Seismic Safety Task Force, which developed policy proposals.

Beam-to-Beam Impact Behavior of Reinforced Concrete Frames under Severe Ground Motions

2011 ◽  
Vol 243-249 ◽  
pp. 1210-1218
Author(s):  
Guo Hui Huang ◽  
Zheng He
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Ground Motions ◽  
Impact Behavior ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Contact Impact ◽  
Reinforced Concrete Frame Structures ◽  
The Impact

The beam-to-beam impact behavior during the progressive collapse progress of reinforced concrete frame structures under severe ground motions is studied in which three types of impact are included, i.e. 1) contact-impact between one-end failed active beam and intact passive beam; 2) contact-impact between two-end failed active beam and intact passive beam, and 3) contact-impact of one-end failed active beam and one-end failed passive beam. As the first step, the initial impact conditions are established based on the principles of the kinematics and the structural dynamics. Then, the velocities of the beams at the impact instant and the locations of the impact would occur are derived. A so-called impact mass factor is introduced in the paper and determined through the principle of equivalent energy. The history of contact force between the beams involved in the impact is evaluated by the Hertz-damp model. The responses of the passive beam are calculated by solving the equation of motion of a generalized single degree of freedom system.

Comparison and Evaluation of Retrofitting Different Modes of Concrete Structures by FRP

2015 ◽  
Vol 1129 ◽  
pp. 242-248
Author(s):  
Hamed Makhdoumi ◽  
Seyyed Hesam Madani ◽  
Mehdi Shahraki ◽  
Mostafa Khodarahmi ◽  
Naser Nosratzehi
Keyword(s):  
Earthquake Engineering ◽  
Structural Engineering ◽  
Failure Modes ◽  
Concrete Structures ◽  
Steel Structures ◽  
Concrete Frames ◽  
Internal Defects ◽  
Concrete Frame ◽  
Recent Earthquakes ◽  
Shear Bending

Abstract. After recent earthquakes in the majority of seismic areas around the world including our country Iran and considering the irretrievable casualties and economic lost due to these earthquakes, natural catastrophic mitigation committees, research and scientific centers that are responsible for providing structural and seismic codes presented the concept of performance design, study of lifelines and retrofit and rehabilitation of existing and vital structures and the majority of researches in the field of earthquake engineering and structural engineering is focused on retrofit of structures considering economic and feasibility problems. Considering the increasing use of concrete structures in Iran and their substituting for steel structures ( due to weaknesses, constructional problems and defects) and considering the internal defects and failure modes, these structures should be retrofitted against earthquakes or preparations should be provided to decrease and minimize failure modes. concrete frames that consist of beam, column and connection is a essential part of concrete structures. Internal defect of concrete frame results in failure modes such as debonding and delamination in beams, buckling and torsion in column, local crashing in connection. Considering the several benefits of FRP sheets and their increasing use during years, these composites can be used for compressive-tensile, shear, bending, torsional retrofitting as well as for ductility increasing. In this study different types of failure modes of concrete frames and internal defects of them that lead to collapse are investigated. In addition different cases of retrofitting by FRP sheets to prevent failure modes and exciting defect are presented and these cases are compared.

International visions and goals for the Earthquake Engineering Research Institute

2003 ◽  
Vol 36 (2) ◽  
pp. 103-107
Author(s):  
C.D. Poland ◽  
S.M. Alcocer
Keyword(s):  
Earthquake Engineering ◽  
Seismic Vulnerability ◽  
The United States ◽  
Capital Investments ◽  
Seismic Safety ◽  
Engineering Research ◽  
History Of ◽  
Tools And Techniques ◽  
Collaborative Efforts ◽  
Research Institute

The Earthquake Engineering Research Institute (EERI) has recently added public advocacy for seismic safety to its rich history of facilitating the discussion amongst earthquake scientists and engineers. In recognition of its unique role as the authoritative source for information in the United States, EERI also seeks to partner with other nations to develop information for use worldwide. In 2002, EERI began forming cooperation agreements with organizations in other countries that encourage the exchange of information, collaborative efforts in learning from earthquakes, joint memberships, development of mitigation tools and techniques, and access to seminars, conferences, and technical publications. The ultimate goal of the program is to arrest the growth of seismic vulnerability worldwide and thereby save lives, protect capital investments, and minimize economic impacts.

scholarly journals Determination of Damage in Reinforced Concrete Frames with Shear Walls Using Self-Organizing Feature Map

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Mehdi Nikoo ◽  
Łukasz Sadowski ◽  
Faezehossadat Khademi ◽  
Mohammad Nikoo
Keyword(s):  
Reinforced Concrete ◽  
Learning Algorithm ◽  
Nonlinear Dynamic Analysis ◽  
Shear Walls ◽  
Concrete Frames ◽  
Function Type ◽  
Reinforced Concrete Frames ◽  
Feature Map ◽  
Concrete Frame ◽  
Self Organizing

The paper presents the use of a self-organizing feature map (SOFM) for determining damage in reinforced concrete frames with shear walls. For this purpose, a concrete frame with a shear wall was subjected to nonlinear dynamic analysis. The SOFM was optimized using the genetic algorithm (GA) in order to determine the number of layers, number of nodes in the hidden layer, transfer function type, and learning algorithm. The obtained model was compared with linear regression (LR) and nonlinear regression (NonLR) models and also the radial basis function (RBF) of a neural network. It was concluded that the SOFM, when optimized with the GA, has more strength, flexibility, and accuracy.

Nonlinear Dynamic Analysis of Rigid - Loose Coupling Bidirectional Vibrating-Crushing System

2014 ◽  
Vol 496-500 ◽  
pp. 1193-1196
Author(s):  
Jun Cui Zhang ◽  
Li Cheng Wang
Keyword(s):  
Structural Characteristics ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Carl Jung ◽  
Loose Coupling ◽  
History Of ◽  
Working Principle ◽  
Left And Right ◽  
The Impact ◽  
Two Sides

The vibratory crusher with two cavities and four jaws is a new superfine crusher, which is a nonlinear vibrating system with rigid - loose coupling. In order to make clear the dynamics performance of the crusher at work, a model of rigid - loose coupling bidirectional vibrating-crushing system is established, according to the structural characteristics and working principle of the crusher. By using four-order Carl Jung Kutta method,we have gained the time history of displacement, velocity, and acceleration, the displacement spectrum and the hysteretic impact force. From it we can see that the vibration of mass to the left and right side is asymmetric, and the impact of the mass on bulk materials of two sides is asymmetric, although the model is structurally symmetrical.

Investigating the Relationship Between Self-Esteem and Stigma Among Young Adults With History of Suicide Attempts

Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder
Keyword(s):  
Young Adults ◽  
Suicide Attempts ◽  
Self Esteem ◽  
High Risk Population ◽  
High Functioning ◽  
People With Mental Illness ◽  
History Of ◽  
The Individual ◽  
The Impact ◽  
The Relationship

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.

The Film World’s Cooperative Store: Institutions and Films of the 1930s and 1940s

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
World War Ii ◽  
Meat Products ◽  
Public Information ◽  
Early History ◽  
World War ◽  
International Context ◽  
German Occupation ◽  
History Of ◽  
The Uk ◽  
The Impact

This chapter traces the early history of state-sponsored informational filmmaking in Denmark, emphasising its organisation as a ‘cooperative’ of organisations and government agencies. After an account of the establishment and early development of the agency Dansk Kulturfilm in the 1930s, the chapter considers two of its earliest productions, both process films documenting the manufacture of bricks and meat products. The broader context of documentary in Denmark is fleshed out with an account of the production and reception of Poul Henningsen’s seminal film Danmark (1935), and the international context is accounted for with an overview of the development of state-supported filmmaking in the UK, Italy and Germany. Developments in the funding and output of Dansk Kulturfilm up to World War II are outlined, followed by an account of the impact of the German Occupation of Denmark on domestic informational film. The establishment of the Danish Government Film Committee or Ministeriernes Filmudvalg kick-started aprofessionalisation of state-sponsored filmmaking, and two wartime public information films are briefly analysed as examples of its early output. The chapter concludes with an account of the relations between the Danish Resistance and an emerging generation of documentarists.

Sign in / Sign up

Export Citation Format

Share Document