The conventional bracing frame (CBF) systems show a limited drift capacity before buckling subjected to seismic loads. So, the induced damage in the structure reduces the strength and stiffness. In the last two decades, self-centering (SC) systems have been developed to resolve the deficiencies of the conventional seismic-resistant systems. In SC systems, the structural damage and residual drift are negligible, while they provide sufficient strength and stiffness. In these systems, prestressed elements are used to provide the initial stiffness. On the other hand, the steel plate shear wall, bracing, beam connection to the column provide energy dissipation mechanism. These elements are used as replaceable fuses after sever earthquakes. When the force applied to the structure is greater than the initial prestressing force, the gap created in the structure causes the energy dissipating elements to work. The main feature of SC systems is that they return to zero deformation after each load cycle. So, the post tensioned elements must remain elastic to be able to reduce the residual displacement. This property of the systems represents flag-shaped hysteresis lateral load-deformation curves.
Among the engineering community, three methods of equivalent lateral forces (ELF), dynamic spectral analysis and dynamic time history analysis are commonly used for seismic analysis of structures. The endurance time (ET) method is a new method for seismic analysis and also for performance-based design of structures. In this method, the structure is subjected to special ET accelerations in which the dynamic response of the structure increases with time. The time needed for the structural failure index (such as the   maximum drift of stories) to reach a certain level of performance or failure is defined as the structural ET. As a result, a structure that has a longer ET, has better performance against earthquakes.
The main advantages of the ET method include: 1) by providing a suitable estimate of the structural response in each time history analysis, saves a lot of computational time for seismic evaluation, 2) the nonlinear properties of the structures may be considered which can be used for a variety of structures and complex behavior, 3) this method has a simple concept and principles for engineering applications, and 4) this method has a high capability for experimental work with a shake table.
In the current research, the self-centering buckling restraining column braced frame (SC-BRC-BF) system was examined. This system not only increases the drift capacity, it also reduces damage and residual drift in the system. The SC-BRC-BF system consists of two rigid cores connected by buckling resistance columns (BRC) between tha adjacent floors. The BRCs are used as replaceable fuses to dissipate the input energy and to reduce the seismic responses. Vertical post tensioned cable is used to restore the system. For this purpose, a preliminary design approach was introduced for SC-BRC-BF systems with 3, 6 and 9 stories via SAP 2000 software. The simulation of structures under time history analysis and ET method was done via OpenSees software fin a 2D framework. Different seismic responses were investigated including: 1) roof drift, 2) the maximum strain of core elements, 3) drift concentration factor (DCF), and 4) Inter-story drift. The response of structures was examined at both DBE (Design Base Earthquake) and MCE (Maximum Considered Earthquake) levels. Comparing the responses from ET method and the conventional time-history method, the error rate does not exceed 10 and 15 % at the DBE and the MCE levels, respectively. The results obtained from seismic evaluation using the two mentioned approaches, corroborated the high efficiency of ET method with a few number of time history analyzes.

The existence of a diverse range of hazards and crisis centers around the border cities represents the use of different planning approaches to resilience and reduce the damage caused by crises (both natural and abnormal) in these cities. Border cities are one of the most sensitive areas that can be vulnerable to the dangers if they are not prepared to deal with and are not properly equipped. In border cities, due to the special strategic and border position, special socio-cultural topography, special economic-political conditions, vulnerabilities and threats, special conditions in terms of risk prevail; Considering the strategic position of these areas and considering the conceptual territory, content in this research, the most important issues in the study of the border cities of Abadan and Khorramshahr in geo-strategic, geo-economics, geo-culture, physical and institutional dimensions are: border geostrategic position, heterogeneous socio-cultural structure, specific geographical and environmental conditions, environmental pollutants (dust and natural resources pollution), history of endangerment and political, ethnic and religious tensions in border cities and special economic, physical and social conditions resulting from the occurrence of the imposed war. According to the proposed cases, the scope of the present study, specifically the border cities of Abadan and Khorramshahr as the largest border cities of Khuzestan province, with an active economic field on a regional and national scale, studies the specific social and cultural context, the border-water location and the experience of the imposed war. What is needed is a revision of traditional planning approaches to urban hazards management and the use of new tools in planning (compilation of resilience scenarios). In this study, foresight and hazards management based on urban resilience scenarios are considered.
 
 
Methodology
The present study is "applied-theoretical" in terms of purpose, and based on the nature and method, it is "descriptive-analytical". Research Methods according to the purpose of the research, is a combination of quantitative-survey and qualitative methods. Data collection tools and information in this research have been done by studying library-documentary sources, field surveys (survey, obtaining expert opinions) and referring to relevant organizations. The statistical population of the present study is academic experts, experts and institutional-organizational managers who have sufficient knowledge and experience in the field of urban resilience and the field of study. These experts were selected and questioned based on the method of "purposive sampling (expert samples) and chain-referral ". For structural analysis of urban resilience drives based on the ability of experts to respond and the complexity of methods, steps and conditions of Delphi technique, a total of (45) academic experts, managers and institutional-organizational experts were selected as the sample. The indicators and drivers of this research are the selected dimensions of urban resilience, including social, economic, physical-infrastructural, ecological and hazards dimensions. In this regard, urban resilience drivers were identified according to the opinion of experts and expert opinions (Delphi technique) and then, these factors were prioritized based on the degree of importance and uncertainty, and the most key factors were identified using the cross-impact balance analysis method and "micmac" software. For scenario writing and questionnaire analysis, cross-impact balance method and "ScenarioWizard" software were used that finally with the opinion of experts, favorable and compatible scenarios of resilience of the studied border cities were developed.
 
Discussion of Results
In line with the main purpose of the present study, to extract the key drivers of resilience, the cross-impact analysis method was used to identify the impact of these drivers. According to analysis performed, among the 46 factors examined (by analyzing the direct and indirect effects and calculating the displacement coefficient of each of the variables in different conditions), (18) agents were extracted and selected as key drivers of resilience in the border cities of Abadan and Khorramshahr. For the sake of scenario compilation, based on (18) selected key drivers and effective on urban resilience, possible situations of urban resilience were formulated. In order to formulate possible situations through surveys and interviews with experts, a scenario basket was prepared for (18) key factors; based on the analysis and possible situations facing the resilience of the studied cities, a total of (54) different situations were plotted for (18) key drivers influencing resilience. Considering the size of the matrix and its dimensions with size (54 × 54), with the help of scenario software and based on the questionnaire data, combined scenarios that included all possible situations were analyzed, the output of which was "521 possible scenarios", "14 high compatibility scenarios" and "3 strong scenarios". Accordingly, three scenarios with very high scores were identified as strong (probable) scenarios in the resilience of the studied cities that among them, one scenario shows favorable conditions and the other two scenarios show critical conditions. It was also detected for believable scenarios (with high compatibility) (14 scenarios). Also (521) weak (possible) scenarios were identified that due to the large number of them, addressing this number of scenarios is not the purpose of this study.
 
Conclusion
Findings related to the analysis of urban resilience scenarios showed that most of the scenarios are in static situations (continuation of the existing trend in resilience of Abadan and Khorramshahr border cities) and critical. Out of the total number of possible scenarios, three scenarios were identified as "strong resilience scenarios" based on the total value of the adjustment value and the total impact score index. Among the strong scenarios, one scenario has favorable situations and the other two scenarios represent critical situations. In this regard, considering the prevailing situation of Abadan and Khorramshahr urban resilience drives, the best scenario is to select the first scenario drives, otherwise, the conditions governing the second and third scenarios and the continuation of the status quo will be the scenarios governing urban resilience drives. In general, it can be said that urban resilience based on scenario writing is a systematic and future-oriented approach to managing the existing and upcoming risks and challenge by creating integration and effective interaction between the dimensions of resilience, key drivers, considering resilience priorities and taking steps based on the presentation of strategies for turning unfavorable situations into favorable, on a local scale, regional and cross-border in the border cities of Abadan and Khorramshahr can be presented.
 
Keywords: Cross-impact balance analysis, Urban Resilience, Scenario Compilation, boundary cities, Hazards, Abadan and Khorramshahr.