Search results

The purpose of this paper is to examine why building owners are often reluctant to adopt adequate mitigation measures despite the vulnerability of their buildings to earthquake disasters, by exploring the economic-related barriers to earthquake mitigation decisions.

A case study research method was adopted and interviews chosen as the method of data collection.

Critical economic-related impediments that inhibited seismic retrofitting of earthquake-prone buildings were revealed in this study. Economic-related barriers identified include perception about financial involvement in retrofitting, property market conditions, high insurance premiums and deductibles, and the high cost of retrofitting. The availability of financial incentives such as low interest loans, tax deductibles, the implementation of a risk-based insurance premium scale and promoting increased knowledge and awareness of seismic risks and mitigation measures in the property market place are likely to address the economic-related challenges faced by property owners when undertaking seismic retrofitting projects. The provision of financial incentives specifically for seismic retrofitting should be introduced in policy-implementation programme tailored to local governments’ level of risks exposure and available resources.

The recommendations provided in this study suggest strategies and answers to questions aimed at understanding the types of incentives that city councils and environmental hazard managers should focus on in their attempt to ensure that property owners actively participate in earthquake risk mitigation.

This paper adopts a holistic perspective for investigating earthquake risk mitigation by examining the opinions of the different stakeholders involved in seismic retrofit decisions.

Seismic vulnerability evaluation of various public structures, especially school buildings, is very crucial for designing hazard mitigation initiatives in seismic prone areas. The city of Mymensingh is at great risk of earthquake because of its geographical location, geological structure and proximity to active faults. The city is famous for its ancient and renowned educational institutes that need to be evaluated for understanding the seismic performance of the building during an earthquake. This study aims to evaluate the seismic vulnerability of educational buildings of Mymensingh city using rapid visual screening (RVS) and index based approach.

RVS procedure includes field survey and secondary source assessment for evaluating structural vulnerability attributes. Analytical hierarchy process is applied to develop an index focusing on systematic attributes of vulnerability based on expert opinions. Then, a composite vulnerability map is developed combining both structural and systematic vulnerability score providing an equal weight.

This study evaluates the seismic vulnerability of 458 educational buildings of Mymensingh city and the result shows that 23.14% educational building has high, 46.29% has moderate and 26.86% has moderately low and only 3.71% buildings has the low seismic vulnerability. This study expected to be helpful in resource targeting and prioritizing seismic hazard mitigation activities for education buildings of Mymensingh city.

This study endeavors to present a comprehensive vulnerability assessment method by integrating RVS and index based approach that incorporates both structural and systematic dimensions of vulnerability. The result is expected to be helpful in the formulation of disaster prevention policy for vulnerable educational buildings and development of the earthquake-resistant building codes for the new building construction in Mymensingh city.

The purpose of this paper is to study the effects of viscoelastic links between two adjacent buildings for pounding mitigation under white-noise seismic input.

A formulation is first extracted for the effective modal damping ratios of the system. Then, two single DOF linear buildings connected by viscoelastic links are considered with both classical and non-classical damping schemes. The inelastic behavior is also taken into account by using equivalent natural frequencies and damping ratios of the buildings. The effect of ground dominant frequency and damping on the displacement response is also investigated by using Kanai‒Tajimi filtered white noise as the random input.

The difference between classical and non-classical damping is shown to be less than 20 percent, implying the permission in using the simpler classical damping scheme. Finally, the problem is extended to two-storey buildings, where using viscoelastic links only at the top story level of the buildings is shown to be sufficient for controlling individual, as well as relative, motions of the structures.

Results demonstrate that the use of link with a moderate stiffness may reduce the stiffer building displacement up to approximately 20 percent in comparison to the free displacement, while the seismic pounding of the adjacent buildings is effectively controlled. Further, an upper limit of link stiffness is obtained for preventing the increase in the stiffer building displacement, which may be exceeded by the minimum link stiffness necessary for pounding prevention if small gap size exists.

Portugal experienced very destructive earthquakes in the past, such as the well-known “Lisbon earthquake” in 1755. With such in mind, accurate estimates of human and economic losses can play a significant role in providing various societal key players with objective information for response strategies. This paper aims to present the contribution of the most recent study in Portugal (PRISE) concerning comprehensive seismic risk assessment, which can be used as good practice and reproduced in different contexts.

PRISE (earthquake loss assessment of the Portuguese building stock) covered three main lines of research, corresponding to the three components typically considered in any seismic risk assessment study: the characterization of the seismic hazard, the identification of the exposure to earthquakes and loss potential and the vulnerability of the exposed assets. Each of these components has been fully characterized through the collection of census and local data (exposure), used to carry out nonlinear analysis (hazard and fragility).

By involving different research institutions and partners with extensive knowledge and expertise in the earthquake domains, the developed model is capable of producing economic and human earthquake loss estimates in real time (through an innovative Web-based platform) or for specific event scenarios, considering exposed population, residential and industrial buildings. The platform uses open-source tools and hence, it can be reproduced in other countries or contexts.

Research wise, the hazard, vulnerability and exposure models can still be significantly improved, e.g. by adding critical infrastructure (hospitals, school buildings and bridges) or updating the nonlinear models, for more accurate loss predictions.

The findings and loss estimates for different earthquake scenarios show that planned interventions are required. Decision-makers and other relevant stakeholders (Civil Protection) can make use of the developed platform to produce specific estimates, to test the effect of different retrofitting interventions or to plan for emergency scenarios.

A real-time Web-based framework to estimate building damage and economic/human losses because of seismic events has been developed, aiming to provide the Portuguese Civil Protection and other playmakers with a unique platform for planning and preparing for emergency scenarios.

The purpose of this paper is to examine the behavioural and sociological impediments to successful implementation of earthquake hazard mitigation and to recommend possible intervention strategies.

Data were gathered through a case study methodology and interviews adopted as the research strategy. A semi‐structured questionnaire was chosen as a data‐collection instrument, with 33 interviews conducted for various stakeholders involved in seismic retrofit decision‐making process.

The research main findings include the role of risk perception in diminishing earthquake hazard mitigation, difficulties in assessing benefits and values of seismic retrofit implementation and the hazard mitigation approach adopted by governmental organisations. The findings suggested that stakeholders involved in retrofit decision‐making should have a good understanding of the risks faced as well as the implications of their decisions.

The paper investigates earthquake hazard mitigation of commercial buildings at the stakeholders‐level by adopting a multidisciplinary approach that incorporated decision sciences, policy perspectives and socio‐behavioural perspectives. The findings highlight the significance of stakeholders approach to foster adequate mitigation of earthquake risks.

Argues that, while the Commonwealth of Pennsylvania (USA) is found to be a low to moderate risk area in terms of seismic vulnerability, it is vulnerable to future episodes which could be quite threatening to a sizeable population. Degree of seismic vulnerability varies across the Commonwealth. Pursuant to assessing Pennsylvania’s earthquake preparedness, the Commonwealth’s various state agencies (n = 12) and the campuses comprising Pennsylvania’s State System of Higher Education (n = 14) were asked to complete a mail‐questionnaire which sought to determine their degree of earthquake experience, risk assessment activity, mitigation activity, and planning for response and recovery. A response rate of 78 per cent was attained. The experience, activity, and planning levels were found to be consistently low. These findings are consistent with research literature which describes the circumstances under which hazard reduction is likely to occur.

The purpose of this paper is to examine the effectiveness of building codes in earthquake risk mitigation in Taiwan.

Using probabilistic risk analysis tools with available data, this study assesses the exceedance probability of extensive damage limit for general buildings in their 50‐year useful lives. The buildings were classified into 15 categories according to their construction materials and building height. Then, the effects of construction materials, building height and construction years are detected.

The exceedance probabilities of extensive damage limit for all of the investigated buildings in their 50‐year useful lives are on the order of 10⁻². The effect of construction materials and building height on seismic risk of buildings is decreasing with the development of a seismic design code. Significant discrepancy of seismic risk still exists among some buildings.

Seismic risk analysis requires quite restrictive statistical idealizations for the relevant probabilistic terms in the mathematical formulation. The problem of imperfect simplification and lack of sufficient empirical data has shown the research needs for improvements of seismic risk assessment. The questions of what constitutes acceptable risk for various performance levels and how safe is safe enough remain context‐specific.

Although probabilistic risk analysis provides a tool for quantifying the probability of structural failure, current earthquake‐resistant design procedures do not relate performance levels to probability. The paper explores some probability information for current earthquake‐resistant design for general buildings during their 50‐year useful lives and the information may provide some valuable information for future code calibration.

Viscous dampers are commonly used in large span cable-stayed bridges to mitigate seismic effects and have achieved great success.

However, the nonlinear analysis on damper parameters is usually computational intensive and nonobjective. To address these issues, this paper proposes a simplified method to determine the viscous damper parameters for double-tower cable-stayed bridges. An empirical formula of the equivalent damping ratio of viscous dampers is established through decoupling nonclassical damping structures and linearization of nonlinear viscous dampers. Shaking table tests are conducted to verify the feasibility of the proposed method. Moreover, this simplified method has been proved in long-span cable-stayed bridges.

The feasibility of this method is verified by the simplified model shaking table test. This simplified method for determining the parameters of viscous dampers is verified in cable-stayed bridges with different spans.

This simplified method has been validated in cable-stayed bridges with various spans.

Until the Loma Prieta earthquake of 17 October 1989, also known as the “World Series earthquake” or the “San Francisco earthquake,” many of us may have considered earthquakes a remote danger. But instantaneous television transmission from the interrupted World Series game and frightening images of the collapsed Cypress Viaduct and the burning Marina district transformed this incident from a distant disaster into a phenomenon that touched us all. The Loma Prieta earthquake was followed in December 1990 by the inaccurate but widely publicized New Madrid earthquake prediction. Despite its inaccuracy, this prediction alerted the public to the fact that the largest earthquake ever to have occurred in the United States occurred not in California or Alaska, but in Missouri, and that a large earthquake could occur there again. Americans are discovering that few places are immune to the possibility of an earthquake.

The purpose of this study is the evaluation of the cost and benefits of earthquake protection of buildings to verify whether the legislative push, through tax incentives, will produce results and lead to a redevelopment of private real estate assets.

Through contingent valuation, this research aims to measure the propensity of homeowners to invest in the seismic security of their properties. The sample of homeowners was selected in a southern Italy city, which was characterized by a medium-high seismic hazard. The willingness to pay, once made independent from the family income, was compared with the actual cost of a seismic retrofitting technique to assess its cost-effectiveness.

The analysis developed on an example case shows that the economic sustainability of the intervention is only verified when considering the current tax incentives for this type of intervention.

Choosing to introduce a system to compulsory insurance against seismic risk could certainly be a strong incentive for the implementation of retrofitting interventions on private real estate assets. In this direction, investigations like this can be fundamental to establish the fair risk premium.

The need for effective seismic risk mitigation policies is also based on the growing awareness of the, often fatal, effects of seismic events, emphasized by the recent medium and high intensity events that hit Italy. The issue of the security of residential buildings is therefore a very topical issue in view of their high seismic vulnerability and the vast number of buildings requiring major seismic retrofitting. Therefore, the propensity of owners to intervene in improving the seismic performance of their properties can be crucial in seismic risk mitigation.