سید محمدحسین نوری رحیم آبادی

The use of prestressed concrete, has begun progress today and on this basis, both experimental and theoretical has strong backing, but this technique is less concerned with steel, and especially when the combination of concrete and steel is used, the lack of instructions becomes more apparent. In this paper, by presenting the proposed increase in load method, the first results of the plastic analysis of a single-span beam were compared with the strain increase method and the experiment and then, the method of analysis of a continuous double beam with combine of stiffness and flexible method, such as a bridge, has been investigated and finally, the variables of cable length, eccentricity of the cable, and the thickness of the slab in terms of performance optimization, are illustrated by the diagram. It has been found that in the combinatorial method analysis , the inversion of smaller matrices is required compared to the stiffness method, and  the results in the optimization section are shown, adding cables will increase the final load bearing in this sample, and a larger eccentricity will cause a larger internal resistance in the beam. Also, although the thickness of the concrete slab strength, increases the final capacity in these specimens, it does not affect the elastic capacity in pre-tension before concrete.

Paying attention to the operational processes of emergency or crisis management has widened in the country that can be cited the legal requirements of the prospectus document at 1404 horizons and the policies of the system related to establishing responsible organizations for crisis management. Business Continuity Management Systems (BCMS) with the requirements of ISO 22301 are factors reducing potential hazards for key activities of the municipality of Tehran. This research describes the standard challenges in the municipality of Tehran's district. This descriptive-applied research, crisis cases are identified by using questionnaires, interviews, and group seminars through Delphi method. In the following, by analyzing the consequences Business Impact Analysis (BIA) in four major missions such as safety, health, credibility of the organization and citizens' dissatisfaction, important events of crisis were identified using the relative weighting indicator. At the final stage of Delphi, the consensus reached its ultimate goal by assessing the probability of occurrence and severity of events, the unacceptable risk determines The findings showed that the average score is more than mean, if the subject's score on the Likert scale is higher than the median, the attitude toward the subject is considered positive. At 99% confidence level, Kolmogorov-Smirnov test was significant (p-value=0.05). Therefore, a nonparametric test should be used. Spearman correlation coefficients were the largest among the research variables (0.559). In the risk analysis section, the risk number of disruptive events of vital activity was derived from the probability and severity of the event between 1 to 16. By analyzing the outcomes of Business Impact Analysis ((BIA) from six main operating factors of organization services such as violation of laws, financial damages, environment, social and security consequences, organizational credibility, possible risk of any outcome at stopping the activity is calculated by considering the probability of occurrence and velocity of the event. In order to achieve the first priority of municipality activities, with the Delphi method, in several steps, priorities out of 208 critical activities fell to 56 and 38 respectively. Finally, a final agreement was reached on the 10 main activities. More important events for the first year include waste collection, snow removal, IT support services, emergency management, management of emergency response, and emergency services.The maximum number of risks obtained for the emergency event is related to lack of coordination between organizations, traffic problems, and blocking the roads, lack of preparation and earthquake above six Richter.

In the present work, a feasibility study has been carried out in order to investigate the suitability of the use of skeletal double layer grid systems as the ceilings and walls of residential, educational, hospital, commercial and administrative buildings in seismic areas by a series of the nonlinear static as well as dynamic time history analyses of representative models. In the case of the sample single story buildings designed in accordance with the common Allowable Stress Design methods, the pushover analysis results have indicated that a lighter structure with higher stiffness and lateral load carrying capacity can be achieved compared with a similar building composed of the moment resisting frame system. It has been demonstrated that with the imposition of appropriate limitations on member slenderness ratios for a few critical members, the ductility of the structure can be improved considerably. Also, the influence of the slope of the post buckling curve representing the member behavior has been found to be remarkable. A comparison of the response of the structure under the influence of three translational components of ground motion with single component excitation has demonstrated the significance of the consideration of the vertical component of ground motion in the analysis and design of such building structures. With due consideration of the lightweight and high indeterminacy of the structural system under consideration, the preliminary investigation carried out here has revealed that the proposed system is a potential candidate for the mass production of common types of building structures in seismic areas and hence deserves further theoretical and experimental investigations.