جستجوی مقالات مرتبط با کلیدواژه « تاب آوری » در نشریات گروه « عمران »

A resilient rail system has the ability to return to its normal operation quickly after losing its performance when an accident happens. In this paper, a method is proposed to increase the resilience of the rail network through the optimal location of the relief train in order to reopen the damaged railroad segment and to allocate it to the vulnerable rail segments of the network. To this end, the exposure of link index is proposed to determine the vulnerability of each rail link in terms of the importance of that link in the network and its accessibility to road as a support system in emergency. Considering the specific operating conditions of the problem, a bi-objective mathematical programming model is proposed to maximize the cooperative coverage of the vulnerable links of the network and minimize the total emergency travel time of relief travel. To solve this model, the Augmented Epsilon-Constrained Method (AUGMECON) has been used to determine the optimal Pareto solutions. In order to illustrate the true applicability of the proposed methodology and verify the obtained results, the rail network of Iran has been adopted as a case study and its results have been analyzed.

Reinforced-Concrete Shear Wall (RCSW) is a common lateral resisting system especially in mid and high-rise structures. This popularity among engineers is due to high ductility and in-plane stiffness of the RCSWs. RCSWs have shown good performance as seismic load-bearing systems in past earthquakes. However, the main disadvantage of RCSWs is the crushing of concrete at the foot of the wall and as a result the buckling of the reinforcement in this area, which makes it difficult and, in some cases, impossible to repair after the earthquake. As a solution, using Buckling-Restrained Brace (BRB) as boundary elements at the base of the RCSWs is proposed and investigated in this research. For this purpose, two sets of 6 and 12-storey structures with conventional RCSW and BRB-RCSW as lateral resisting system were designed, and their seismic response were assessed through static (monotonic and cyclic), dynamic Nonlinear Time History (NLTH) and Incremental Nonlinear Dynamic Analyses (NIDA). The results indicate improved structural performance and an increase of response modification factor from 4.4 in conventional RCSW to 5.47 in RCSW-BRB. Furthermore, the proposed system prevents the induced damage at the foot of the RCSW while the replaceable BRBs act as the fuses, increasing the resiliency of the structure. So that the behavior factor of the frame equipped with buckling-restrained braces increased by 30 percent in the 6-story building and 20 percent in the 12-story building.

The conventional approach to River Basin Flood Management (RBFM) focuses on increasing the safety and security of drainage systems against heavy rainfalls. Recent floods in urban catchments have highlighted the need for a more resilient approach that also considers the floods consequences. Resilience of a RBFM system refers to a systems ability to withstand various precipitation events, reduce flood damage, and restore normal conditions. This study proposes a framework for selecting flood management options in a hierarchical system based on social resilience indicators, focusing on social aspects. In this study, behavior of RBFM systems in response and recovery from varying rainfall events defines the resilience. To operationalize the framework a set of social response, social recovery capacity, resistance point, and warning point-related indicators have been defined. A hierarchical fuzzy system has been developed to quantify the indicators, considering the uncertainties in social variables and avoiding dimensional incosistency. Using this approach in the Gorganrood river basin demonstrated the effectiveness of selected flood risk management options in terms of resilience, by considering various social resilience indicators, as compared with traditional decision-making methods. Comparing the response-recovery curves for different management options has highlighted the importance of defining different resilience indicators to determine the behavior of the RBFM system after performance failure. Finally, the results of this study suggest that the proposed indicators can be employed as decision-making criteria in selecting various management options based on the behavior of the river basin system under rainfall events with different return periods.

A seismic-resistant structure not only should provide safety for the residents but also it should minimize the financial loss resulting from the earthquake. Therefore, it must be demonstrated that the structure will remain in acceptable situation after the earthquakes with various intensities. The past has shown that, the financial loss of earthquake for the structures that have been designed based on performance objectives of current seismic codes, is considerable and this results in additional problems. Therefore, it seems that upgrading performance objectives for structures can significantly reduce earthquake losses. Improving the performance objectives of structures is associated with increasing the initial cost of the project. But reducing the damage of resilient structures and the cost of repairing of damaged components in these structures can reduce the ratio of initial cost to total cost.In this study, the effect of enhanced performance objectives in increasing the initial cost of the project and reducing the costs of repairing the damaged components of concrete structures is discussed. To investigate this issue, 3, 5, 10 and 15 storey regular concrete frame structures are modeled and designed based on Design Basis Earthquake of current seismic codes (DBE) and also based on Maximum Considered Earthquake (MCE) for the same performance objectives. The loss and repairing cost of the structures are evaluated according to FEMA-P58 guideline and using PACT software under 6 near-field and 5 far-field records. The results of this study show that, enhancing the design objective of concrete frame structures increases initial cost of lateral resisting frames (beams and columns) and the total cost of the building by 23% and 5%, respectively. Whereas the repair costs of the structure and the whole building are reduced by 43% and 18%, respectively, which ultimately leads to reduction of the life cycle cost for the structures by 13%.

Among the several definitions for the resilience of transport networks, this paper deals with the (WIPW). WIPW is an innovative metric for measuring the resilience of transport networks. Due to the uncertainty in occurrence time of the disruptive events in the pre-crisis stage, in this paper, based on two new indicators: (1) time and (2) the form of the time-resilience diagram, a coefficient called the strategy implementation efficiency E (λi) is presented and using it, the (WIPW) is modified. At the end of the paper, a numerical example is provided, in the example, 9 different portfolios referred to as (R), (B), (R + B), (R ̃), (B ̃), (R ̃ + B ̃), (R*), (B*) and (R* + B*), are selected and for all the portfolios E (λi), (WIPW) and the modified () are compared. The results showed that if the optimal portfolio is selected based on WIPW and WIPW the R, and (R ̃) is selected as optimal portfolio respectively. Comparison of the selected bridges in R and R ̃ shows that the L-M Bridge in R has been replaced by G-H in R ̃. The replacement of these two bridges changed the implementation time index from 1.1128 for R to 1.1643 for R ̃ and the diagram form index from 1.0201 for R to 1.0213 for R ̃ and Finally, the implementation efficiency will be improved from 1.1352 for R to 1.1852 for R ̃.

This study aims to provide a model for estimating the direct social loss incurred by communities in Iran due to the loss of life resulting from the earthquake-induced damage to infrastructure systems. Once estimated, the direct social losses caused by an earthquake can be used to quantify and analyze community resilience. Numerous past studies have focused on estimating the direct and indirect economic consequences of earthquake-induced infrastructure failure. However, a review of the relevant literature demonstrates a lack of appropriate models for calculating social costs associated with such events considering the characteristics of the subject community. Research is needed to develop suitable analytical models that quantify the social costs of earthquakes. Previous research studies have proposed using concepts like the value of a statistical life to quantify the social losses caused by hazards such as accidents, environmental pollution, and Terroristic Attacks and Fatal Diseases. Accordingly, past studies on the quantification of community seismic resilience used the value of a statistical life for countries such as the United States in conjunction with the exchange rate to arrive at costs incurred by a community due to earthquake-induced casualties. Since Iran is a country with high seismicity, underestimating the damage caused by the death of individuals and as a result, incorrect estimation of the amount of social loss incurred by the community may misguide the vulnerability reduction efforts. This will have adverse economic, political, and social consequences for the community. Several methods have been proposed to calculate the value of a statistical life, the most important of which are "Revealed Preference" and "Stated Preference." This study uses the revealed preference method to calculate the value of a statistical. This manuscript reports the methodology adopted for collecting the relevant data and the development of the model that estimates the value of a statistical life.

Statement of Problem: The city of Tehran as a political, social and economic capital has a decisive role in the fate of the country. Tehran with a population of more than 8 million people is the 24th most populous city in the world. 8.10% of the population has a share equal to 21% of the country's gross domestic product (GDP) and more than 50% of tax revenues as well as 55% of bank deposits are provided from the city and province of Tehran. At the same time, the city still suffers from many problems, the most important of which is the unfavorable situation of builders, to the extent that according to the same study and a survey of construction industry experts in Tehran, 42.5% of them consider the quality of construction in Tehran poor or catastrophic. Dilapidated and dysfunctional structures in the heart of Tehran and with very difficult accesses add to the concern about possible crises. Although several programs have been carried out in the field of repair and renovation of worn-out structures, but so far the city administration has not met expectations and we still face this problem. The purpose of this study is to introduce the effective first steps to create a codified method (planning) for implementation so that the results can guarantee the quality of ongoing construction. The research method was descriptive and correlational and a questionnaire was used for this purpose. The statistical population is the target of professional engineers of Tehran Building Engineering Organization. 120 questionnaires were analyzed by SPSS and SmartPLS software. Based on the findings of this study, the use of six important factors in planning, including: implementation of construction quality assurance insurance, mandatory contractor in construction, accurate and complete implementation of the building technical certificate, adjustment and increase of engineers' fees along with increasing public awareness and change and Amend national building regulations. According to the findings of this study, it can be said that the most important finding of this study is that the process necessary to establish insurance quality assurance of the builder is clearly explained.

Accepetance of the fact that the working context of civil projects is challenging can enhance the resiliency capacity and will increase the project management concentration for improving and developing the software and hardware capabilities to facilitate project success achievement. This article is documented based on a research results in macro-hydropower plants projects management context to represent a new project management approach named as “Resilient Project Management”. Thematic analysis is the chosen research methodology in this study. Different qualitative and quantitative techniques are used in the study. Systematic literature reviewe, opened interviews and closed questionaries are the tools to gather datas inorder to demonostrate the framework. Results showed that there are six main demensions and related requirements to implements resilient project management approach in project management context. Management and leadership style, Organizational structure and human Resources, Working processes and resources, Performance index management and control, Maintenance management and readiness efforts and Chrises control and management are the dimensions of resilient project management approach.

So far, several studies have been conducted to prioritize the allocation of resources to bridges to improve the resilience of transportation networks. Many of these studies have examined the identification of important bridges in a fixed network without changing the topology. But in many networks, there is a possibility of structural change and development in the future that will lead to changes in network density and topology. This changes the importance of the bridges relative to the basic conditions in the decision to allocate the resource. Also, identifying bridges that are smoothly prioritized regardless of future network changes will help to make optimal decisions in the face of resource constraints. In this paper, an indicator called the cumulative importance of bridges is presented, which determines the optimal portfolio by considering the changes in the importance of bridges in different periods of development. A numerical example is provided to illustrate how to use this index. The results of this example show that the use of the index causes the selection of bridges to be different from the optimal selected portfolio with conventional approaches.

The aim of this paper is to investigate the impact of emergency response forces on the number of survivors during the disaster. In this research, a model is presented to calculate the optimal number of forces for each mode depending on the available budget. Frank Wolff's algorithm was used to assign ground forces, and for more realism, the impact of post-disaster links failure was also considered in ground forces. The proposed model in this study was solved using Particle Swarm Optimization algorithm. One of the most important results of this study is the effectiveness of air mode in particular in high budgets and variable effectiveness of land forces in different budgets. Also, it has been shown that in lower budgets, the effect of budget increases is greater than high budgets. In other words, the increase in the number of survivors in the fixed amount of funding increases from 98% for low budgets to 2% for high budgets.

Nowadays, in the aftermath of disastrous events, communities are trying to quickly return to normal status. Therefore, in recent years, the issue of resiliency has gained much more attention. The social dimension, which is one of the main components of resiliency, involves investigating the social capacity of communities under critical conditions. The main objective of the current study is to evaluate and investigate the level of social resiliency in Ilam City using a descriptive analytical methodology. The statistical population of the study includes the residents of Ilam City, among which 381 participants were selected using multi-step cluster random sampling based on the proportions of the population in selected areas. The questionnaire of the study was developed by the researcher; its validity was confirmed using formal validity while its reliability was confirmed using Cronbach’s Alpha which was equal to 0.85. The obtained data were analyzed using descriptive and inferential statistics in SPSS software application. The results show that social resiliency in Ilam City is not at an acceptable level. Moreover, among the selected neighborhoods, the Saadi Neighborhood with an average score of 3.10 has the highest social resiliency, while Banbarz Neighborhood with an average score of 1.64 has the lowest level of social resiliency.