فهرست مطالب ashkan khodabandehlou

Throughout history, structural engineers have always been trying to design optimal structures that are always cheap due to limited resources, and at the same time meet all existing design limitations. After the great damages caused by the earthquakes in the 1990s in America and Japan, the seismic design regulations made significant changes. Although there were not many casualties in these earthquakes, huge economic losses were left, which clearly revealed that the goal of life safety should not be only the design criteria should be used, and more performance levels should be controlled and verified in the designs. During the last few years, performance-based design has been introduced in regulations and expanded significantly, on the other hand, the improvement of computing power of computers and hardware systems has made it possible for people to use optimization methods and use advanced nonlinear analysis. Therefore, today we can use a meta-heuristic algorithm for the design of new structures to find the best design and perform a dynamic analysis to find the response of the structure. This possibility was previously only possible for the evaluation of existing buildings, and the performance evaluation methods at that time were defined by regulations. And various recipes were introduced. The main goal of performance-based design is to design structures whose behavior is predictable. The current method of designing structures is based on design by resistance method and includes estimating the base shear in the structure and its distribution in height and determining the required resistance of structural components against incoming loads, regardless of the deficiencies that exist in this method, expressing the behavior of the components A structure, only through resistance, in many cases does not give a suitable answer. In fact, the purpose of seismic design based on performance is to enable designers to design structures whose performance is predictable, because the involvement of employers in choosing the level of risk in the design in question at different earthquake levels requires knowing. The way the structure works in different earthquake levels. According to the design regulations, structural members are designed in such a way that they can withstand the incoming forces with a suitable safety margin that depends on the design method. After designing the structural members for the incoming forces, displacement controls are also performed in some cases the purpose of this research is to evaluate the seismic safety of steel frames with optimized cross convergent bracing in the framework of performance-based design approach. This research consists of two main steps. In the first step, two three-span ten-story frames with a cross bracing system with the position of the bracing in the middle opening and the side openings, using the meta-heuristic algorithm of the center of mass in the framework of the performance-based design method, and considering the weight of the structure as the objective function and the external penalty function method have been optimized. In this phase of the study, OpenSees software was used to perform nonlinear modeling and analysis, and MATLAB software was used to implement the optimization problem. In the second step, the seismic safety of the frames resulting from the optimization process has been investigated using incremental dynamic analysis. According to the obtained results, it was observed that placing the brace in the side openings reduces the seismic safety by almost 10% compared to the bracing frames with the placement of the brace in the middle opening.

Today, the large production of cement in the world, especially in Iran, has become critical. Because the production of cement has caused the production of carbon dioxide gas and increased air pollution in cities. Therefore, in this research, the combination of bentonite and zeolite was used to increase the quality of concrete and reduce the consumption of stone and cement powder. The laboratory program of this research includes five mixed designs with the simultaneous combination of bentonite and zeolite in different ratios of 0%, 2.5%, 5%, 7.5% and 10% by weight of cement in SCC concrete. The results of this research showed that the simultaneous use of zeolite and bentonite up to 5% by weight of cement can have acceptable results. It increases the compressive strength by 8% and the tensile strength by 11%. But these pozzolans increase the hardness of SCC concrete due to their high water absorption and the possibility of the concrete being blocked behind the rebar density increases.

The main goal of this research is to evaluate the nonlinear seismic behavior of special RC moment with and without viscous dampers at the floor level. In this research, 2 high-rise three-dimensional RC building frames of 12 and 16 stories, each frame with 8 models, 4 models with and 4 models without viscous damper at the floor level, located in the area with High seismicity on type 3 soil is considered. In order to seismic analysis of frames with and without viscous dampers, nonlinear static analysis method was used according to the second appendix of Iran earthquake regulations, fourth edition. The initial dimensions of the structural elements of the studied frames and the thickness of the roof slabs have been determined in ETABS-V15 and SAFE2014 software, respectively, and finally, modeling, gravity and lateral loading, and nonlinear static analysis of the studied frames have been performed in the SAP2000-V19 software. The results show that the change in the sections of beams and columns from square to rectangle in frames with and without viscous damper causes an increase in the relative lateral displacement of the floors, as well as an increase in the number of openings along the Y axis (model 1 compared to 3), and an increase in the length of the opening along the Y axis (model 1 Compared to 4), in frames with and without viscous damper, it reduces the absolute lateral displacement of floors.

Performance-based design is a new approach to topics of the seismic design of structures, which unlike the traditional methods of force-based design, is based on changing the location of the structure. The use of this approach in the process of structure design results in the access to structures with proper performance and an acceptable level of reliability. The main goal of this contribution is to investigate the impact of near- and far- field earthquakes on the collapse capacity and fragility of performance based optimization of RC moment frames using the center of mass meta-heuristic algorithm. Push over analysis has been utilized in the optimization process to control the responses of the studied frames at functional levels and incremental dynamic analysis has been used to evaluate the fragility of the obtained optimal frames. According to the results for the collapse margin ratio and the adjusted collapse margin ratio for the 3-, 6-, and 12-story frames, it is indicated that the collapse margin ratio and therefore the seismic safety under far-field earthquakes are 7%, 16%, and 8% higher than those of the near-field earthquakes, respectively. In other words, the optimized frames in this study against near-field earthquakes have low seismic safety and more fragility than far-field earthquakes.

In the present research, the seismic fragility and collapse capacity of concrete moment frames have been investigated by considering different ratios for the weak beam-strong column rule in the optimization process in the performance-based design framework. In order to implement performance-based optimization, the center of mass metaheuristic algorithm has been applied in this research. The philosophy of design approach based on performance and even traditional design methods allows the structure to suffer damage facing strong and relatively strong earthquakes. Therefore, in order to estimate the level of safety of the structure against earthquakes, it seems necessary to use quantitative indicators of seismic safety and the collapse capacity of the structure. In order to predict the collapse capacity of each optimal structure, using incremental dynamic analysis, the modified collapse safety margin ratio under far and near fault earthquakes has been calculated. Two examples, 3-span three and six floor frames have been studied in this research, which are designed in the performance-based optimization framework and considering the coefficients of 0.8, 1.2 and 1.6 to control the weak beam-strong column rule in the optimization process. The results indicate that increasing the rigidity of the column compared to the beam in this research actually affects the ductility of the structure, and by choosing structures with greater rigidity of the column compared to the beam, it leads to an increase in the collapse capacity and a decrease in the fragility of the structure.

The formation of the short column phenomenon in reinforced concrete structures has caused design engineers to study the behaviour of such structures. One of the conditions that lead to the formation of a short column is the placement of the structure in a steep position. In this paper, two 8- and 16-story structures were modelled once on a flat surface and again on a sloping site, and their sections were designed using equivalent static analysis. Then, using nonlinear time history analysis, the behaviour of these structures in the plastic region was compared. Structures were modelled in Sap2000v20 software and SeismoSignal.v2018 software was used to scale the accelerometers used in nonlinear time history analysis. Examining the results, it was observed that the formation of short column phenomenon in reinforced concrete structures with special bending frame system has a negative effect on the seismic response of structures; It increases the displacement of the floors, increases the drift of the structure and also creates a mechanism (or the formation of plastic joints). For example, based on the results obtained from 8 and 16 storey structures with and without short columns, it was observed that the average drift of 8 and 16 storey structures with short columns was 19% and 7.1% in the X direction more than the structure, respectively. It has no short columns and also in the Y direction, the average drift of 8 and 16 storey structures with short columns is 7% and 12.8% more than the structure without short columns, respectively.

In this paper, the seismic behavior of reinforced concrete (RC) high-rise buildings with frame-core tube systems as one of the lateral bearing systems are studied. In order to investigate the effect of the core tube system on the seismic behavior of the high-rise building, the structural model is evaluated in two cases with the inner core tube and without the inner core tube. Three methods of equivalent static analysis, dynamic nonlinear time history analysis and nonlinear static analysis (push-over analysis) are used. Also, a 25-story high-rise building with a frame-core tube system having voids in the last floors is implemented. The results showed that the use of RC core as a central tube significantly reduces the lateral displacement and drift of floors. Also, the results obtained from the nonlinear static analysis indicated that using the central RC core, the ultimate capacity of the building as well as the ductility of the building increase significantly. Finally, the results obtained from the nonlinear time history showed that the nonlinear static analysis have good accuracy in calculating the maximum displacement of the structure.

In recent years, the use of helical screws in reinforced concrete components has been developed. Practical results of these experiments have shown that spiral reinforcement (SR) has improved seismic performance compared to other conventional methods. Experience has shown that by applying torsion in concrete members, due to the principal tensile stresses in the diameter of each element, the member elements of torsional structures with spiral patterns will expand. Due to the design of the expansion of torsional cracks in the cross-section, these cracks are relatively ideally perpendicular to the cross-section of the torsion reinforcement. The research results so far clearly show that the use of rectangular helical bolts increases the bearing capacity. Also, in this method, with a constant ratio of transverse reinforcement, the ductility condition is improved compared to conventional bends in workshops. Finally, the use of helical reinforcement in structural members increases the shear, flexural and axial strength. Commonly used braces require two end hooks to support the anchor. For the length of these two hooks, a large amount of steel material is needed for each closing brace, which increases the weight and price of the steel. This process is not required, and this type of reinforcement reduces the weight of the steel and saves money due to the reduction of steel consumption compared to conventional braces. The effect of SR on the formation of cracks and the member's behaviour after cracks has also been tested.According to the researches, it is observed that so far, the effect of continuous closures as well as the effect of changing different parameters in the enclosure in columns with a square cross-section with continuous rebars has not been done. Regarding the confinement of concrete members with reinforcement, considering the cases mentioned about the importance and role of transverse struts in the performance of structural components, the purpose of this study is to investigate the performance of helical reinforcement in comparison with conventional transverse reinforcements in square reinforced concrete columns.  Also, the effect of changing various parameters such as yield stress of reinforcements (high-strength steel with normal strength), cross-section reinforcement and cross-sectional column dimensions on behavioral performance, including load-bearing capacity and ductility, in columns with this type of arch and analysis. In this study, the finite element analysis method has been used. The results show that the capacity and ductility of the column enclosed by the winding is higher than that of the column retained by the conventional tension. Also, in the column held by the twist, the column withstands less stress after loading, so it can be said less damage in this column will be obtained. In the load-displacement curves drawn for the column, at the beginning of the vertical branch up to a certain load, the behaviour of the columns is the same. Until the peak is reached, the stiffness decreases with increasing stiffness, and in the area after the apex, the softening behaviour increase. As the spacing of the bolts and the pitch of the windings increases, the behaviour of the columns in the two modes becomes closer to each other. It shows a relatively similar behaviour, and the difference in their capacity also becomes much smaller. Ductility is also reduced. Increasing the pitch of the windings has a greater effect on the capacity of the column than increasing the distance of the windings. By increasing the distance of the turns, the capacity of the column enclosed by the tortoise decreases sharply. However, in these conditions, the column enclosed by the tortoise performs better than the column enclosed by the arch. The results show that by increasing the cross-sectional dimensions of the column, the rebars withstand less stress, and the column capacity also increases. Also, keeping the number of rebars constant and increasing the cross-sectional dimensions to a certain extent increases the capacity, and then increasing the dimensions without increasing the number of rebars does not have much effect on the column capacity. The results show that with the increasing yield stress of the rebars, the capacity of the column has increased. Increasing the strength of the rebars reduces the stress in the concrete, resulting in less damage.

Diagonal lattice systems are extensively structured systems of tubular and frame structures and can drastically reduce the weight of the structure and significantly improve the behavior of high-rise buildings by significantly reducing shear lameness. In this paper, the number of partitions, the angle and the optimal structure of single and double layer diagonal grid systems in tall buildings are determined. For this purpose, a computer program and meta-innovative solutions based on genetic algorithm and Caramba have been used as the engine of structural analysis. In these analyzes, the relationship between input factors including distance between two layers, angle and number of elements and number of vertical and horizontal divisions with output factors obtained from structural analysis using Caramba engine, including maximum deformations, weight and Pi delta effect were obtained. Based on the results obtained from genetic algorithms and meta-heuristic solutions, the weights obtained for diagonal lattice systems are more than one layer compared to two-layer systems. In addition, due to lower weight, simpler geometric structure, higher execution speed, no need for highly skilled technical force, lower energy consumption, less architectural space, creating more open spaces and better exposure in single-layer systems than two-layer, These systems are recommended for use in high-rise buildings.

Owing to the destruction of high-rise buildings during recent earthquakes, the use of a structural system of reinforced concrete moment frame with viscoelastic damper causes a loss of seismic energy and consequently reduces lateral displacement. In this study a high-Rise, 20-Storey, three-dimensional reinforced concrete frame with 8 Models, of which 4 models with moment frame structural system and 4 models with moment frame + viscoelastic damping system in two directions of X, Y located in the high seismic zone (A=0.3g) on the soil type III is considered. The aim of the present study is to investigate the horizontal lateral displacement (absolute and relative) of the stories, the base shear of frames under gravity loads, and lateral loads of the earthquake.  In order to modeling the viscoelastic materials, the Kelvin-Voigt model and to determine damping ratio(ζ) of frames with viscoelastic damper, stiffness coefficient (Kv) and damping coefficient (Cv) of viscoelastic dampers, the modal strain energy method have been applied. For seismic analysis of models without and with dampers, dynamic analysis of nonlinear time history via direct integration and modal (FNA) methods have been utilized, respectively.  Geometric modeling of all frames was done using the SAP2000-V15 software. The results indicate that with increasing span length (model 2 compared to model 1 and model 4 compared to model 3) and increasing the height of stories (model 3 compared to model 1 and Model 4 compared to model 2), the maximum absolute lateral and relative displacement of stories, and base shear along with X, Y without and with viscoelastic damper have an increasing trend. Also, the maximum percentage increase of the mentioned models with damper compared to without damper along with X, Y has decreased

Soil-structure interaction is one of the important and influential factors on the seismic behavior of structures, especially reinforced concrete structures. In this study, the effect of soil-structure interaction on a 9-story reinforced concrete structure with a flexural frame system designed based on low-risk seismic requirements and for nonlinear analysis with OpenSees finite element software in two different modes with rigid base without considering the interaction And with a flexible base, the effect of soil-structure interaction has been modeled and evaluated. The results show that due to the interaction, the base shear, the shear within the floors and the amount of relative displacement are reduced, while the actual periodicity of the building and the absolute displacement of the floors is increased.

The need for more high-rise buildings that have complex reactions to earthquakes makes controlling soil-structure interactions particularly important. Also, the architectural and aerodynamic requirements of high-rise buildings that lead to post-deposition necessitate further studies is inevitable on the effects of post-depositional and soil-structure interactions. In this study, a three-dimensional, 25 floors reinforced concrete frame with a particular moment frame structural system along the x,y line in a very dangerous area (a =0.3g) with two models with the height of floors (3.2-4.2) has regular (1-12) and with post-depositional (13-25) floors on the soil (I, II, and III) is assumed without soil-structure interaction. The purpose of the present study was to determine the maximum horizontal lateral displacement (absolute, drift) floors, base shear and invert anchor frames. To model the sub-foundation soil from Themickwolf's cone model, determination of coefficient of dynamic stiffness of spring and damping coefficient using discrete model based cone model in half homogeneous space for the analysis of soil-structure interaction from the subsurface method. For seismic load analysis, the nonlinear time history dynamic analysis method by direct integration method under seven accelerometers was used and geometric modelling was performed on all sap2000-v18 software. The result shows that with change in soil type (II to I, III to I, and III to II) without and with soil-structure interaction, the trend of the maximum lateral displacement (absolute, drift) in two model (1 and 2) of storeys (1-25) along (x, y) increasing, maximum percent increase in lateral displacement (absolute-drift) from the floors (13-25) to the floors (1-12) respectively, lateral displacement (decrease-increase) and soil (II to I) without and with soil-structure interaction from the floors (1–25) due to stay periodic the soil (I, II) does not change. Also, the maximum base shear is reduced of model 2 to 1 the soils (i, ii, iii) without and with interaction along (x, y), and the maximum overturn anchor is increased.

Improving the mechanical properties of concrete with the help of fibers is considered as one of the common methods of concrete processing. Addition of fibers to concrete increases the energy absorption and ductility of concrete and prevents the spread of cracks. Steel, polypropylene and glass fibers are the most widely used fibers. In addition, new types of macro-synthetic fibers have been introduced. In this research, in order to improve the mechanical properties of concrete, a new type of macro-synthetic fibers has been used. Samples reinforced with 2, 4, 6 and 8% of fibers were evaluated using various compressive, flexural, tensile tests as well as elastic coefficient determination tests and their optimal consumption was selected. In this research, it has been tried that the test conditions are as compatible as possible with the industry conditions so that the final results of the research are in good agreement with the current situation of the concrete industry and can be used. Comparison of test results showed that, as expected, fiber-reinforced concretes have higher compressive, flexural, tensile strength and tensile strength than conventional concretes. In addition, between different percentages of fibers in concrete, in samples with percentages greater than 2%, the rate of increase of different strengths is lower than in the case without fibers. Therefore, considering the cost of macro synthetic fibers, the most suitable percentage for reinforcing concrete with them was introduced as 2%.

One of the most important factors in the design of the structures is providing seismic resistance against earthquakes-induced forces. Buildings might be subjected to stimulations of earthquake seismic components, which affect the structure in three perpendicular directions. In estimations of the earthquake forces, the vertical component is usually neglected or understated. However, the earthquake vertical component can lead to drastic stress changes in the structural elements, especially the concrete slabs with opening. In this study, the effect of earthquake vertical component on concrete slabs with opening has been investigated. Three concrete structures with 5, 8, and 12 stories and slab openings of 0, 15, 30, and 45 percent were subjected to the effect of the near-field record of Bam, Northridge, and El Centro earthquakes. Non-linear time history analysis was used to comparatively study the structural displacements and stresses. The results indicated that the contribution of vertical earthquake component in slabs displacements was not significant compared to that of three direction combination. On the other hand, it was inferred that the acquired stresses have a direct relationship with deformations generated in the slabs, so that in models with larger displacements, higher stress levels were detected. For both the three direction combination and the vertical direction earthquakes, increasing the opening percentage would result in growing more stress in concrete slabs. Generally, the maximum produced stress in the slabs was in some cases about sixty percent of the maximum stresses induced by three directional combined earthquakes.

Progressive failure is the spread of a chain of damage from one member to another in a structure that, following local damage caused by the removal of one or more load-bearing members, begins and is disproportionately transferred to the other members of the structure. The whole or destruction becomes a large part of the structure. In the discussion of progressive failure, determining the element that has the greatest potential for progressive failure is important. Because by strengthening this element, the performance of the structure can be improved. In this paper, the progressive failure of two reinforced concrete structures with a different number of floors (10 and 16-storey buildings) using nonlinear dynamic analysis is investigated. The analysis and design of this structure has been done in SAP 2000 software and modeling has been done by creating local failure in the middle column and corner column under the influence of three different acceleration angles. The relative displacement of the floors, the viscosity index based on the maximum base cut and the formation of plastic joints, and the possibility of progressive failure based on existing standards and design based on the GSA guideline alternative method have been investigated. The results of this study show that in reinforced concrete buildings, the bending frame of the corner columns has the highest potential for progressive failure. In addition, the results show that structures with higher heights perform better against progressive failure.

Local damage caused by the removal of one or more elements in structures lead to progressive collapse and results in partly damage to the structure, increasing damage rate and total collapse of the structure. Most buildings are designed and constructed regardless of their vulnerability to such loads. The purpose of this study is to investigate the progressive collapse in the moment frame system in a 12-story building with three openings in two different states. The frame is firstly studied with single cross columns and secondly considering two first floors using semi-buried cross columns in concrete. In order to investigate the effect of the number of lower composite floors on the overall behavior of the frame and the effect of system changes on the height of the structure from the composite frame to the steel frame, the SAP2000 software has been used for nonlinear static analysis and the deformability was studied. Dynamic nonlinear analysis of the two structures is also was performed using OpenSees software under the loading recommendation by the GSA code. The results of the analysis show that the adjacent column to the removed column bears the largest axial force and the probability of failure in this column is more than the other ones in the first floor. Therefore, this column should be designed with a higher safety factor. Also, the beam located in the middle of the first floor in the composite frame has the highest DCR and its probability of failure is greater than the other beams.

Nowadays, the use of control systems in buildings has been increased and the importance of vibration reduction of structures is considered more than ever. In addition to improve the dynamic behavior of buildings, control systems can be installed between adjacent buildings as activated, semi-active and inactivated systems. Fluid viscous dampers are one of the most important approaches for inactivated control systems in which the dynamic response of two adjacent buildings reduces according to the high resistance of the viscous fluid. The main purpose of this study is the use of control systems in two similar adjacent buildings to reduce the entire system response which will be the analytical study of the impact of viscous dampers to control system performance. In order to provide the analysis and to study the dynamic behavior improvement of different adjacent buildings connected with dampers, two models of the original sample was investigated. All examples are different from each other and response analysis and time history was provided using SAP 2000 software. According to the acquired results, the effect of fluid viscous dampers for tall buildings is less than the shorter ones. Moreover, these dampers are more efficiently working for adjacent buildings with different heights rather than buildings with the same height.

This research are considered and analyzed threedimensional  high rise building three frames of 28-story reinforcedconcrete in each direction X,Y structural structure of a tube in tube,In the zone of high relative risk(A=0.3g),With fixed number and  bays the length,different heights and types of soil(I, III), Once without affecting soil-structure interaction Once again, the effects of soil-structure interaction are considered and analyzed. The purpose of the present study is to determine the maximum lateral displacement frames floors of gravity loads(dead,live)and earthquake loads. In order to analyze the structure of the structurethe soil-structureintraction impact of the substructure is assumed to be used for the  modeling of the sub-surface soil from the cone model,the structure of the structure and the determination of the dynamic hardening coefficient and  damping coefficient  soil of the discrete model based on the cone model in the homogeneous space stream.In order to analyze earth quake loads  in the studied models,a  dynamic analysis of the nonlinear time history of the modal method under seven  accelerations accelerations.The geometric modeling of the all frames with shear walls in the SAP 2000-V17 software package was performed.The results show that with increasing elevation of floors(model 1 to 3),the maximum lateral displacment floors on type I soil in the direction of X increase in the direction Y is significant increase,in model ,in the model 2 to 1by changing the type of soil type, the maximum lateral displacment floors with out and with Soil-Structure intraction in the each two direction is dramatic increase.

The construction of high-rise structures around the world is rapidly increasing and this trend has been accelerated following the rapid economic growth and expansion of cities and increasing demand for space in populated areas. As these skyscrapers reach higher heights, they become a symbol of the power and superiority of technology advancement and economic development. Therefore, the use of new structural systems and modern construction technologies with the aim of reaching taller buildings considered by designers and engineers. In this study, a 26-story structure with 3-story underground with retaining walls is required to design against the lateral soil force of the surrounding area, that has a dual core system with tubular core modelled and dynamic analysis was performed under the influence of earthquake lateral force, and extent of lateral displacement of the structure and changes in force applied to its components were investigated in Sap2000 software. The tube in tube system indicated good performance against gravity and lateral forces and the maximum lateral displacement of the floors was within the permissible range due to the code and height of the structure concerned.

The studies have shown that the site characteristics such as soil layers properties and layer thickness can effect on the ground input motion and might change the acceleration frequency content and seismic duration. This research aims to study the effects of site characteristics on the ground response, and the response of the constructed buildings. In order to study the site effects on the ground seismic response, 14 far and near fault earthquake were considered and linear and nonlinear analysis on four different sites was performed. Additionally, one to four story buildings were modeled and the responses were analyzed using SAP 2000 software. Generally, the ground response related to the far and near fault earthquakes, the seismic input motion is amplified while passing through the earth layers and considering the acceleration, the maximum seismic motion increases. The smaller the maximum input acceleration of the seismic input of far fault earthquake, the less is the nonlinear and linear responses. For the cases with the larger near fault earthquake maximum ground acceleration, the analysis of the response, the response analysis using the linear equivalent approach shows that the soil layer of the input motion is amplified while passing through the soil layers. Comparing the graphs of the maximum acceleration versus the depth for the far fault earthquake, it can be inferred that the procedure cannot be generalized for the entire results of the far fault earthquakes. The maximum displacement in the depth increased with increasing the soil deposits thickness. For the similar stories buildings overlaid on the soil deposits, in both shallow and deep cases, the maximum displacement decreases with depth. On the other hand, the maximum obtained displacement in the linear and nonlinear times history analysis increases while increasing the number of building stories.

In this study, 2 reinforced concrete 3D building frames for a 28-storey building are going to be considered and analyzesThese frames are in both X andYdirections with tube in tube structural system and a flat plate roof with rigid internal core in the shape of H, in a relatively high risk zone (A=0.3 g) on two kinds of soil, with and without soil-structure interaction.The goal of this study is to determine the maximum drift and displacement of the storeys under gravity loads(dead  live) and lateral load of earthquake. A discrete model based on a buried footing Cone Model in homogeneous half space of volf and meek is used to model the soil under the foundation and also to determine dynamic stiffness coefficient and Soil damping cofficient and a substructure method with the footing rigidity assumption is used to analyze the frames with the soil-structure intraction  effect. A dynamic analysis of the nonlinear timeline history of seven accelerograms is used to analyze earthquake load and geometric modeling of all  frames with internal core has been done in sap2000-V17software.The results show that the maximum drift and displacement of the storeys with soil-structure interaction in X and Ydirection was not different with the one without interaction and that they are equal. By changing the type of soil with and without soil-structure interaction, the maximum drift of storeys in X direction had a descending increment process of 22 percent and in Y direction, had 25 percent is increment.

The idea that a building can be uncoupled from the damaging effects of the ground movement produced by a strong earthquake has appealed to inventors and engineers for more than a century. Seismic isolation is effective in reducing seismic demand for buildings and decreasing seismic damage costs. Today the concept has matured into a practical reality and is taking its place as a viable alternate to conventional (fixed base) seismic resistant construction. This study, three bracing frame and three spacial moment frame were modeled and analyzed and the capacity curve wase plotted.The finaly, response modification Factors for steel frames equipped with base isolation were compiled as a table.Finally, based on the results of the analysis, it was observed that the structures equipped with the surface separator have a more obtuse curve than the non-separating state.

After use new materials for use in construction, the invention of various structural forms can be considered as the most important factor in the feasibility of the construction of high-rise structures. The structural form of the building system is a system that tolerates the various combinations of horizontal and vertical loads. The structure is taller and thinner the structural factors of the degree are more important and subsequently the need to choose the structural form is further increased [1]. In this regard, recently, in the design of high-rise structures, a new idea, the tube in tube system, has been presented by Fazlorkhan and Milestone, which has been used in many of the world's tallest structures, including the Oil Standard Building in Chicago and the World Trade Center building in New York. Therefore, in this research, by modeling a concrete structure with a height of 108 m and 28 floors (a basement floor) and adding shear walls to this system and applying different layouts for them, by SAP2000, the seismic performance of the structure under 7 accelerates has been investigated and the base cutting and displacement force of the roof is compared under different modes. The results show that as the location of the shear walls moves from the center of the structure to the outer layer, the seismic response of the high-order structure with the tube in tube system will be improved and the sections can be reduced for the cost-effectiveness of the project.

The design of structures against wind and earthquakes due to losses caused by these phenomena in different countries is very important. Designing of tall buildings should be have comprehensive and complete against the forces of wind and earthquake. Earthquake is one of the world's natural phenomena, so that in recent years the human losses during 1947 and 2005 have been announced about 550 thousand people worldwide. The main goal of this study is to investigate the behavior of resistant reinforced concrete core in high-rise building of the tube in tube system with stairs against earthquakes in building with 100 meters height and 25 floors under the influence of three Accelerogram Bam, Tapas and Northridge via SAP2000 software. Base shear, roof displacement and column axial force compared together. The results of the research showed that modeling stepping on the coordinates of the center of mass has not made a significant change, but rigidity center has mainly changed due to stiffness of stair slab. Also high-rise building's seismic response affected by the earthquake Accelerogram type