نشریه مهندسی سازه و ساخت
سال هشتم شماره 9 (پیاپی 49، آذر 1400)

Due to lack of sufficient concrete strength or change in design guidelines, some RC structures are in need of retrofitting. RC moment resisting frames can be retrofitted through various methods such as different types of braces, steel jackets, steel or concrete shear walls, etc. Retrofitting the structure and reassessing it is only possible if the characteristics of the new compound seismic system are known. In this study, the behavior of the RC moment resisting frame retrofitted with inclined members mesh and steel shear walls in the face of cyclic lateral load is investigated. Three specimens of RC moment resisting frames of the scale 1:3, with identical dimensions, reinforcement and concrete strength were built. Two of the specimens were retrofitted with steel shear walls or inclined members mesh, using the same amount of steel. Finally, stiffness, strength reduction factor, ductility, strength and energy absorption of the samples were calculated and compared. The results show that both retrofitting methods improve the seismic properties of the structure but the inclined tensile member mesh yielded a better performance compared to the steel shear wall. While carrying out the linear or nonlinear analyses of the retrofitting of RC frames, special attention should be paid when equalizing steel shear walls with inclined tensile members due the difference between their stiffness.

The high rate of accidents and work-related damages in construction projects, has converted the construction industry to one of the most dangerous industries. Behavior-based safety as a new approach in safety management emphasizes the unsafe behavior of individuals as the most important cause of accidents more than ever. In order to implement this approach, it is essential to examine the factors that effects on the employee's behavioral safety. The purpose of this research is investigate the effect of organizational conditions on safety climate factors that are the most important Basic factors of staff safety behavior. In this study that was done by the structural equation modeling method, using AMOS 22, in the first stage, the measurement model was evaluated using confirmatory factor analysis; then, the structural model that was designed based on the research hypotheses was analyzed. The calculated indices (RMSEA=0/079; IFI=0/90; CFI=0/91; x^2⁄df=1/995; TLI=0.91) showed the optimal fit of the proposed model of research. Based on these results, management safety commitment has a positive and direct effect on four factors such as safety training and employee empowerment, Safety supervision, Social support and teamwork, as well as safety rules and rewards system. These findings emphasize organizational managers to pay attention about those factors to increase the safety level of staff.

Recent investigations show that graphene oxide nanoparticles (GO) are promising nano-sized additives to enhance the mechanical property of cementitious materials. GO are the product of chemical exfoliation of graphite and contain a range of reactive oxygen functional groups that enable it as a suitable candidate for reaction in cementitious materials through physical functionalization. In this paper, the experimental program is performed to study the mechanical and water transport properties of GO-reinforced cement composites. Experimental results show, adding GO improved the tensile, flexural, and compressive strengths of mortar with the increase in flexural and tensile strength more than that of compressive strength. Especially, the tensile and flexural strength, when the content of GO was 0.05% bwoc, the cement mortar exhibited remarkable increase by 70% and 22% respectively, comparing with those without GO. Particularly, the compressive strength of concrete incorporating 0.1% by weight of cement GO increased by 25% and 50% than those of concrete without GO after curing for 28 days and 90 days respectively. The strengths enhancement can be attributed to the promotion of hydration and the finer pore structure of cement paste incorporating GO. There are thresholds for all mechanical strengths of cement mortar incorporating GO where the GO content exceeds the threshold, the decrease in strength is observed which can be attributed to the deformation of the hydration crystals by the change in the dosage of GO in the matrix. Penetration test results indicate that the incorporation of a very low fraction of GONPs can effectively hinder the ingress of water molecules. It can be concluded that adding GONPs improve the transport properties of concrete which subsequently improves its durability.

The most important feature of the behavior factor is that it allows the structural designer, to be able to evaluate the structural seismic demand, using an elastic analysis, based on force-based principles quickly. In seismic codes such as the 2800Standard, this coefficient is merely dependent on the type of lateral resistance system and is introduced with a fixed number. However, there is a relationship between the behavior factor, ductility (performance level), structural geometric properties, and type of earthquake (near and far). The main purpose of this paper is to establish an accurate intelligent model related to the geometrical characteristics of the structure, performance level and the behavior factor in eccentrically steel frames, under earthquakes near-fault. For this purpose, genetic algorithm is used. Initially a wide database consisting of 12960 data with 3-, 6-, 9-, 12-, 15- and 20- stories, 3 column stiffness types, and 3 brace slenderness types were designed, and analyzed under 20 pulse-type near-fault earthquakes for 4 different performance levels. Two powerful optimization algorithms have been used to generate the proposed relationship. To generate the proposed correlation, 6769 training data were used in the form of PSO and SA algorithms. To validate the proposed correlation, 2257 test data were used to calculate the mean squared error for both algorithms. The results indicate that there is more accuracy in the relation of the PSO algorithm.

Risk management is one of the approaches to the success of construction projects that must be implemented systematically. In classical approaches, project risks are assessed based on two criteria of probability of occurrence and their impact; In the present study, we first identify the risks involved in construction projects. Then paired comparisons were made for weighting and determining the importance of risk factors, then using DEMATEL combined method and network analysis process. to validate the proposed model, based on a case study in the Risk Identification Development Project using the Delphi method at three levels out of 60 identified risks, 18 risks were selected out of five categories of technical, financial and support risks, social, environmental, implementation. They were categorized, and then the extent to which each of these risks impacted the project objectives, the probability of each occurring, and ultimately the degree of importance of each risk. The ranking of identified risks indicates that the main research risks are the executives and technical departments that have gained the highest score using the combined DEMATEL method and the network analysis process, but in terms of impact on other factors, social risk It is of particular importance to others at different stages of work.

Although steel plate shear walls have the inherent advantages of formability and increasing the energy absorption of the lateral load system, there are some shortcomings such as buckling in the early stages of loading and high demand for shear force of the column. In order to address these cases, a new moment connection using steel trapezoidal plate in the form of numerical models of steel shear wall system under monotonic loading and cycles is presented. The main aim of this study is to provide a system of low-thickness steel shear wall that has the same capacity and energy absorption in accordance with the direct connection sample, while at the same time concentrate the plastic joint area on the connection plate. The connection plate acts like a fuse. In spite of conventional steel shear wall systems, the connection of the steel wall plate to the column has not been established and vertical lateral stiffeners have been used to improve its performance. Also, three different thicknesses used for the connection plate. The finite element numerical model was validated with eight test specimens and a good accuracy was established in terms of load-bearing capacity, elastic stiffness, and failure mode. The results of nonlinear static analyses on the developed models showed that the use of the connection plate was able to act as an energy-absorbing member and prevent the boundary elements from entering the plastic status. Therefore, the use of lower cross-section of column elements is possible. There is also no need to follow a weak beam- strong column rule and to use continuous or doubler plates in the panel zone of the column. Finally, it was found that the relationships presented in the AISC regulations are less than 7% to 25% for estimating the angle of the tensile field and the shear capacity.

One type of structural systems that has received growing attention in recent years, includes post-tensioned flat slabs and steel columns. This system has significant economic and professional advantages. But, seismic behavior of the connection between flat slab and steel column, which is principally designed for gravity loads, is in doubt. In this regard, these connections should have sufficient ductility under lateral deformations. Although details for the connections of nonprestressed slabs to steel columns are published in the technical references, which usually include steel shear heads, but specific details for post-tensioned slabs have rarely been published in the literature. In this study, new details have been proposed for the connections of post-tensioned flat slabs to steel columns. These details include horizontal steel plates, vertical steel stiffeners and high strength shear bolts. To evaluate the proposed details, a half scale test specimen was built and was subjected to lateral cyclic loading with increasing amplitude. The test shows that the proposed connection could withstand relatively large displacements up to a drift of 6%, without loss of strength and/or gravity bearing capacity and/or significant failure. According to this study, the proposed details have sufficient ductility under lateral loading and provide a favorable seismic performance.

Numerical models are feasible approach against field studies which are capable of estimating of materials behavior appropriately if material properties are considered exactly. Numerical models are categorized in three sets: Micro, meso and Macro scale. In macro scale, the whole concrete is considered as a one phase material and usually the interaction between concrete-steel is just modeled. In Micro Scale Modelling, the cement-aggregate crystals are evaluated. The other preference of meso scale numerical model is the ability of presenting different phases interaction in multi phase materials such as concrete. This feature is useful in high rate dynamic load such as explosion. To perform meso scale modeling, different random specimens with different contents of aggregates must be produced. In different studies, a unique pattern which could generate real aggregation is not used. Aggregates generated in this study are elliptical, and by controlling the lack of interference with each other, aggregates are randomly assigned into the defined template boundaries. Then, in the next step, the specimen is meshed by choosing dimensions of elements in cubic form. Finally, the prototype is transformed into the input text file of the numerical analysis programs. The comparison between produced aggregate curve and real cure shows good agreement.

Deck-pile pier structural system is one of the most common types of pier construction systems. Corrosion, ship collisions and huge storms cause general and extreme damages, especially in the deck and the splash zone of the wharf. If the location and severity of the damage is known at the early stages of the damage, they can be repaired as soon as possible. One of the available methods for identifying damage in structures, which is based on the changes in the dynamic properties of the structure, is the modal strain energy method. In recent years, modifications have been made to the original version of this method, the Stubbs index, one of which is the consideration of natural frequencies in locating the damage, known as the improved modal strain energy method. In the present study, using both Stubbs index method and improved method, an experimental and numerical study is performed to identify the location and determine the severity of damage in the members located in the deck and splash zone in a real LPG export deck- pile pier (pier number Fourteen) located in the port of Pars-Assaluyeh, in Persian Gulf. The results showed that the improved method has higher accuracy in locating the damage than the Stubbs index method. Also, single and multiple damage, with low and high severity, were predicted with appropriate accuracy by this method.

The resistance of steel structures under accidental loading conditions such as fire is affected by the inherent characteristics of the structure such as redundancy, ductility and joint constraints. On the other hand, due to the action of the structural components exposed to fire, the rigidity of the diaphragm and the performance of the connections are subjected to damage. This paper examines effects of the rigidity of the diaphragm and the shear connections constraints as part of the fire-resistant properties of steel braced frames. Two modes of operation of the floors in the form of rigid diaphragm and soft diaphragm, as well as two modes of operation of shear connections in the form of hinged and rolled joints, have been evaluated under a fire scenario. The effect of gravity and fire loads on a 10-story steel braced frame is simulated in these cases using numerical analysis techniques using finite element method. Analysis show that fire resistance time of braced frames and structural collapse mechanisms are severely affected by the presence or absence of diaphragms as well as tensile constraints on shear joints. As in the case of the existence rigid diaphragm of the structure, it undergoes a total collapse in a short time, and also in the absence of tensile constraints of the joints, the collapse mechanism locally changes position. Analysis results can also help engineers understand local and general responses to steel braced frames under fire loading.

Because of lightweight concrete has less mechanical properties than normal concrete, one of the objectives of engineering society is to design light weight concrete with a structural mechanical characteristic suitable for optimum resistance. Therefore, in this paper, using the Taguchi method to studied the parameters influencing of the compressive strength of Self-Compacting Light Weight Structural Concrete containing Nano-Silica. According to the Taguchi data, a total of 9 mixed designs were considered, taking into account the effects of the whole content, which included the ratio of water to cement materials, the ratio of Nano-silica to cement materials, the ratio of superplasticizer to cement materials, and the ratio of aggregate to total concrete weight. The results show that the maximum effect on the compressive strength is related to the change in water-to-cement ratio, which is about 56.5% of the impact on the pressure resistance. The percentage of Nano-silica to cement was 36.1. The third degree of impact on the compressive strength of the concrete is related to the effect of the superplasticizer ratio on the cement, which is about 7%, and finally the weight ratio of aggregates to the total concrete volume with an impact of about 0.4% in the fourth grade is important. Finally, the quality criterion was considered for lightweight concrete so that the optimal state for achieving Self-Compacting Light Weight Structural Concrete containing Nano-Silica with water to cement ratio was 0.35, the percentage of Nano-silica to cement was 4%, the superplasticizer percentage was 0.8%, the ratio of aggregate to total concrete volume was 0.48 obtained.

In this study, hysteresis behavior and energy absorption rate of steel shear walls in reinforced sheets CFRP, GFRP and the effect of grooves with different patterns under cycling have analyzed using the finite element method. For this purpose, the accuracy of the responses obtained from the software is compared with the experimental model. Sensitivity analysis is then performed on the dimensions and types of elements used in the analysis. All models are subjected to cyclic loading in according with ATC-24 code. After simulating each of the models in the ABACUS, the results of analysis include shear capacity, energy absorption and the maximum of these parameters were evaluated during the analysis of the models and compared with each other. The best model also in two parts of reinforcement and groove, under four different earthquakes, behavior seismic has been studied. The results show that the reinforced polymer sheets on the shear wall have a direct effect on the seismic performance and the pattern of stress distribution is directly related to how grooves. Also among the models, the use of CFRP with horizontal alignment has the best seismic performance.Key words: Steel shear wall, Reinforced polymer sheets, Energy absorption, Hysteresis curve, Performance improvement

Corrosion of steel reinforcement in concrete structures is one of the most influencing factors in the loss of durability of reinforced concrete (RC) structures. Neglecting the effects of corrosion has unpleasant consequences and may lead to the failure of structures before their designed life time. Corrosion reduces the cross section of the steel reinforcement, changes the mechanical properties of the steel, decreases the strength of the concrete, and ultimately reduces the capacity and ductility of RC structures. In this study, the effects of corrosion on the moment-curve diagram of structural elements are studied and then compared with the approaches recommended by guidelines such as FEMA-356. To evaluate the effect of steel corrosion on the performance of structures, two RC frames (3-storey and 7-storey) are modeled and two corrosion scenarios are applied to beams and columns of the structures. Then, capacity curves of structures as well as design parameters such as ductility coefficients are obtained by nonlinear static (pushover) analysis of the structures considering the effects of corrosion on moment-curvature diagrams of structural elements. The results show that the coefficient of awareness of 0.75 according to the guidelines such as FEMA-356 can lead to overestimate the structural capacity in highly corrosive environment. It also leads to conservative and uneconomic results in a low corrosive environment. It is observed that the capacities of the 3 and 7-storey structures have been decreased between 19 to 36 percent due to corrosion. Results also show that corrosion reduces the structural capacity between 8 to 28 percent.

With the increase in explosive attacks and the need for defensive preparedness, it is possible to consider strategies to improve the safety and resilience of non-structural members and their efficiency. In this paper, the nonlinear performance of a reinforced concrete frame with non-structural steel wall-reinforced interlayer under blast load is investigated. For this, in the first step, a concrete frame with steel wall-reinforced masonry frames, according to the latest recommendation of the Iranian seismic design code, in ABAQUS finite element software under the load of two explosive charges of 300 and 1000 kg by equivalent pressure method. The blast was located at distances of 5, 10, and 15 meters from the base of the structure, and the relative displacement response between the interfaces and the dissipated energy in the whole model were studied. In the second step, the necessity of strengthening this system has been discussed by adopting two strategies: increasing the cross-sectional number of wall-posts and reducing the distances of wall-posts. The results show that the relative displacement of peer-to-peer in the model with the strategy of increasing the cross-sectional number of wall-posts, at the expense of 1000 kg and 300 kg at a distance of 5 m by increasing the angle cross-section from L60x60x6 mm to L80x80x8 mm by 34.20%, respectively. And decreased by 48.25%. This reduction was achieved in the model with the strategy of reducing the distances of the wall posts at the expense of 1000 and 300 kg at a distance of 5 meters, respectively 5.51% and 3.53%, which was more than 2 times the amount of reduction of the first strategy. Also, the depleted energy in the model with the strategy of reducing distances compared to the model with a cross-section of L80x80x8 mm under 1000 kg explosion, more than 2.4 has been obtained.

One of the most important issues in buildings is irregularity in the plan or height of the structure, which causes increasing the seismic damages. In irregularity in height, sudden changes in the dynamic properties of the structure including mass, lateral stiffness and strength of the structure occur. Therefore, the stage of making decision for determining the building configuration has a fundamental importance Irregular buildings must be able to withstand the lateral forces of earthquakes and winds. One of the most common earthquake-resistant systems in steel structures is the bracing system, which has been considered by engineers due to its good performance in previous earthquakes and reduced drift of buildings. However, some architectural constraints may cause the braces to be moved to the story level, which is subjected to irregularity of cutting the lateral bearing system, or the lateral braces may be weakened or removed due to poor supervision in some stories, in which case the story may be irregular. There is very soft story in the building. In this study, 7 scenarios in three states such as regular, very soft irregularity, and irregularity of cutting the lateral bearing system is considered for 5-story frame. These frames are designed based on seismic guidelines of standard 2800, and then, the performance of them has been evaluated by SAP2000 software using analyses methods such as equivalent static, spectral dynamics and time history dynamics under near-fault earthquakes. The aim of this study is to investigate the accuracy of these methods. The results showed that time history dynamic analysis is more accurate than other methods. For example, the error rate of the maximum displacement response of frame with irregularity of cutting the lateral bearing system in equivalent static analysis compared to spectral and time history dynamic analyses are 15% and 77%, respectively.

Progressive collapse is a nonlinear phenomenon that starts from the damage of a part of the structure and ends with the whole structure and its total damage. Therefore, the study of this phenomenon in high-rise and important structures while securing it will ensure the design process of the structure. Progressive collapse usually occurs in the structure due to the loss of one of the main members of the structure, which is usually the desired column. With the sudden removal of a column in the structure, in the node where the column is removed from the structure, there is a displacement that has a seismic nature. In this research, the effect of using steel haunch bracing with different locations in concrete moment frames is investigated under progressive collapse. The purpose of this evaluation was to determine the vulnerability of concrete structures retrofitted with steel haunch bracing as well as the effect of steel haunch bracing in spans and height of the structure, the place of eliminated element (edge or middle) and the number of the story in which the member was removed in the progressive collapse, is studied. A noteworthy point in different cases of component removal is in the wide changes of stresses and change of node displacement and lack of formation of plastic hinges in the members, which can be explained by the proper distribution and placement of steel haunch bracing in spans and height of the structure in the place of elimination of members in the model, there are more structural elements and this issue strengthens the catenary action of the members to transport and transfer load and also the immediate stabilization of the situation.

The Endurance Time method is the method that was considered. In this research,, two 15 and 20 story shear building were evaluated by performance weakness in return periods equal to 475 years by a new ET generation, and the results were compared with the second generation and natural earthquake records In Seismo-Struct software. The Endurance Time curve showed the performance and durability of the structure equipped with a friction damper compared to the structure without the damper. It was also observed that the fourth-generation records of Endurance Time in nonlinear displacements than the second-generation records show results closer to the natural scaled records of the earthquake, and for frame equipped with Rotational Friction Dampers whose period was less than 2 seconds, the results have good accuracy. While for structures with period of more than 4 seconds, there is still a slight difference. It was also observed that the response of 15 and 20 story frames with F series records is 50% different from natural records, while Kd series records are less than 20% different. These results show the quality and accuracy of new generation records of Endurance Time for structures with a period of less than 3 seconds and weakness performance.

In the developing countries, due to low cost, abundance of materials, substantial durability and ease of construction, masonry structures are still common construction system and blocks are conventional type of masonry units in these buildings. Despite the problems faced in utilizing simple blocks such as low out-of-plane strength and inconsistency in construction quality; achieving fast construction, economic solutions and enhancing performance and integrity subjected to in/out of plane loads encouraged civil engineers to make changes in the design and production process of masonry blocks for which interlocking blocks can be considered as an innovative solution. In this experimental study, a novel interlocking cement block were employed to construct small-scale masonry prisms. In two cases of using paste and mortarless interlocking blocks, six standard tests were used to evaluate in-plane behavior, including compressive strength, diagonal tensile strength, and in-plane direct shear strength tests, and out-of-plane behavior including flexural tensile strength in two directions and out-of-plane direct shear strength test of block prisms in the concrete technology laboratory of Shiraz University of Technology and the results were discussed. The proposed blocks can be used simply in practice. The results showed that the innovative blocks, due to the proper design of the appendages, showed appropriate and uniform behavior in terms of in/out of plane strength. In addition, adding paste can improve behavior and strength of the interlocking block.

Respect to the concept of the control structures, the author of this study recently suggested a novel hysteresis damper with named nested-eccentric-cylindrical shells damper (NESD) for increasing the damping in structures.According to the greater ability of the shell structures versus the plate structures, the NESD is designed based on the shell structures. The configuration of the shells in the NESD is designed in such a way that it can be increasing the performance and stability of the device. These members are as well as the multi-springs with the combination of series and parallel form. Also, the configuration of this device is designed by the simple form and with an easy way to install in structures. However, to evaluate the seismic performance of the proposed damper, the NESD used into the structures with various heights with four, eight, and twelve floors and analyzed by dynamic nonlinear time history. The seismic analyses are run with eleven records by particular geography characteristics of seismic hazard zone. In this evaluation, the efficiency of this damper in damping seismic energy and reducing the displacement and base shear responses is approved. In the seismic analysis, Therefore, by modeling this damper in structures, it was found that by using this damper in structures could be a damping of up to 35% of the seismic energy in the structures and reduce an average of 50% in displacement and could cause a reduction of 7 to 27% in the base shear for the structures. However, it was found that the NESD could be better behavior for reducing the response of mid-rise structures.

Pile foundations are one of the significant marine substructure systems for a variety of offshore and onshore facilities. In recent years, helical piles have become common foundation system for marine structures exposed to the reciprocal seawater waves. Moreover, these foundation systems have received particular attention due to several influential parameters, including the limited required time for installing and the ability to be immediately loaded after installation. However, the methods for estimating their bearing capacity is limited. The present study investigates the behavior of three different helical piles under tensile and compressive loading via Frustum Confining Vessel available at Amirkabir University of Technology (FCV-AUT). The under-study piles were single, double, and triple-helix with diameters of 70 and 90 mm. Double and triple-helix piles are designed with two different spacing to helix diameter ratios of 1.5 and 3. These piles were installed in Bandar Anzali sand regarding two loose and medium densities. The soil was prepared by adding 4% humidity for testing. The applied bottom pressure of FCV-AUT was 200 kPa. The results indicated that the helical pile bearing capacity increased due to soil improvement and densification during the special installation procedure. However, during the reciprocal loading, the tensile capacity of helical piles was reduced.

In Concrete-Filled Steel Tubular (CFT) Columns with binding bars, horizontal binding bars arranged along the steel tubes are used to enhance the confinement effects on the core concrete and to postpone the initiation of local buckling. So, they have higher strength, more stiffness, better ductility and larger energy absorption compared to conventional CFT columns. In this paper, the unilateral buckling of steel plates in CFT Columns with binding bars under axial compression is investigated by the Rayleigh-Ritz method, using the shape functions of a rectangular plate with appropriate boundary conditions. It is assumed that the unloaded edges of the steel plate are elastically restrained against rotation. Trigonometrical functions that satisfy the boundary conditions of the rectangular plate are used to define the shape functions. In unilateral buckling, the folled concrete is described as an elastic foundation with high stiffness in compression and without tensile stiffness, such that buckling occurs in only one direction. The Lagrange multiplier technique is used to model the binding bars. The solution algorithms of the problems are written in MATLAB code. The solution of this process is used to obtain the elasto-plastic local buckling load of unilaterally-restrained steel plate with various numbers of binding bolts depends on spacing between them. Finally, the numerical results were compared with experiment results. The excellent agreements of the results verify the accuracy and efficiency of the method.

Selecting and scaling the set of ground-motion records is among the most important challenges in collapse capacity assessment and estimation of structures. In this study, 44 records were considered to estimate the collapse capacity of the structure.Next, the response spectrum matching degree of each ground-motion with the conditional mean spectrum at the inspected hazard level was employed to account for the effect of record selection on the collapse capacity of the structure and appropriate records were selected per each hazard level. Further, the spectral shape factor or epsilon was used to incorporate the effect of spectral shape on collapse capacity. In the first approach, the collapse capacity of the structure was modified for the overall set of selected ground-motions via epsilon according to the level of inspected hazard. In the second approach, the simplified method introduced by Haselton et al. was used to assess the effect of epsilon and modify the collapse capacity of the structure at the inspected hazard level. The results of the modified collapse capacity at the inspected hazard level were collected from three respective methods of record selection. These data were collected using the overall set of ground-motions with the epsilon and the simplified method. The obtained results indicate that the ratio of modified collapse capacity with the effects of record selection and epsilon on collapse capacity, disregarding the record selection and epsilon effects, are 1.216, 1.174, and 1.197 at the hazard level of 2% in 50 years for the three discussed methods, respectively. Ultimately, these three individual methods have rendered approximately equal estimates.

Nowadays, a simple composite floor consisting of the concrete slab and steel castellated beam is considered as one of the most economical floors in the steel structures. However, due to the permanent danger of fire in buildings, it is essential to evaluate the composite floor's behavior against fire. Therefore, in the present study, the performance of the composite floor of the Building of Mehr House in Kermanshah province is investigated as a case study. In this study, non-linear coupling temperature-displacement analysis and explicit method in Finite element software and linear temperature analysis are applied to analyze the models. The results showed that with increasing temperature, the role of steel castellated beam decreased and the role of the concrete part was increased, thus, in the designing and rehabilitating the composite floors by considering the tensile membrane action of the concrete slab, the reinforcement costs could be reduced. Moreover, the results show that the composite floors of the building were designed such that they do not collapse during the fire and lose their operation due to the considerable fire during the fire. finally, predicting the failure of the building during a fire can be investigated due to the loss of strength and stiffness of the columns and connection during the fire.

Earthquake is a natural and unpredictable phenomenon that causes a lot of human and financial losses in many seismic zones of world. Therefore, the prediction of seismic events is one of the most important in earthquake and structure literature. Moreover, planning for crisis prevention as well as taking appropriate decisions after the crisis in urban areas will significantly increase the impact of measures to reduce the seismic risk. One of the computational tools in the risk analysis is the fuzzy logic to predict the possible damages due to natural disasters. Precise scientific principles and many advantages of this tool in analyzing phenomena with probabilistic uncertainties have caused its application to be constantly expanded and developed. In the present paper, the use of fuzzy tools for classification of the structures in Shahrekord (IRAN) has been investigated and the seismic hazard of selected buildings in this city is examined as a sample of existing structures. The results are consistent with the experiences of the recent earthquakes in this country for the vulnerability of buildings in urban areas. Also, the results indicate that the proposed method has good adaptation and the parameters which have been used in the damage assessment, propose good reliable flexibility.

Corrugated steel plate shear wall system (CSPSW) is one of the lateral load resisting systems, which in some cases has better seismic performance than the steel plate shear wall system. In this study, the seismic performance of the corrugated steel shear wall system was investigated. The variables of the present study are the angle of corrugated steel plate (0 to 30 degrees), percentage of steel plate openings (10, 20, and 30), and the number of openings (1, 2, 3, and 4). Abaqus finite element software was used for modeling and analysis. A total of 91 steel shear wall models were subjected to 100 mm displacement and were analyzed by the pushover method. The behavior of steel materials is considered as elastoplastic. The results showed that as the angle of corrugation increased, the yield and ultimate strength increased. The initial stiffness decreased with increasing angle of corrugation. Secondary stiffness also increased initially but decreased afterward, but the ductility decreased. With the increase in the percentage of openings, the yield, and ultimate strength decrease. The initial and secondary stiffness decreased, and the ductility first decreased and then increased. As the number of openings increases, the yield and ultimate strength decrease first and then increase.