Sharif Digital Repository

As population increases in the city, infrastructures have to be developed. Because of the limited financial supplies of the governments and infrastructures and high expenses of which, government is not capable of affording infrastructures to develop cities. Therefore,the government needs to encourage the private section to invest in such project for developing cities.One of the most required infrastructures for cities are parkings. parking spaces are inseparable elements of the Cities; their shortages bring many direct and indirect impacts on the quality of life of the Citizens, including waste citizen’s time in seeking for barely found parking spots, car traffic increase, and surge of... 

In recent years a large number of passive energy dissipating systems developed in accordance with pioneering work on friction dampers which was firstly reported by pall(1979). Uusing Friction dampers reduce the inelastic demand of the structure during severe earthquake motions by sliping and a large portion of input energy dissipated mechanically in friction instead of yielding the main components of the structure. Based on economical purposes, it is valuable to know in which storey and slip force should be employ the friction devices to have an optimized performance of the structure. Due to kinematic conditions of slip and stick stages, as well as transition zones between them in friction... 

The paper presents the results of nonlinear analysis of steel base plates subjected to different combinations of axial and bending forces. The bending forces range from small moments representing small eccentricities to large moments from seismic actions. The results of nonlinear analysis are done on three samples of the column base plate with large moment, small moment and compression axial force are compared to the results of the code. The parameters investigated in this study are as follows: distribution of strain and stresses in the concrete foundation and the steel plate, the strains and stresses in the tensile anchorage bolts, the location of neutral curve under the base plate, the... 

The purpose of this study was to find the optimal position and slip force of friction dampers, for improving the seismic performance of regular and irregular steel structures and comparison of dampers final pattern of these buildings.In this regard, one to six floor regular and irregular buildings were designed. These buildings were modeled three-dimensionally in the OpenSees Software, and were subjected to horizontal components of seven far field accelerogram in order to investigate the need for their rehabilitation. The results of the time history analysis of these buildings showed that inter-story drifts exceeds the acceptance criteria which has been assumed 2.5% according to the Life... 

In the conventional design of buildings, seismic loading codes consider the base shear as an earthquake-induced load, and by distributing this base shear along the height of the structure, members are designed to withstand lateral loads (i.e. earthquake force). The most common form of earthquake force distribution is based on the response of the main mode (first mode) of the elastic structure. But this lateral distribution has two major problems. First, it does not take into account the impact of higher modes on the structural response; and second, the entry of the structure to its inelastic domain in severe earthquakes and the difference resulting from this structural behavior change in... 

In this study, the behavior of box column subjected to constant axial load with cyclic lateral force have been investigated by Finite Element method. The resulf of FE anslysis are in a good agreement with experimental result in predicting of behavior and performance of box column. In order to investigation of behavior uses of some performance indices such as axial shortening, over strength, plastic hinge length, out of plane deformation and rotation capacity. The effect of significant parameter such as axial force to yield strength ratio, flange whidth to thickness ratio of flange, web whith to thickness ratio of web, global slenderness ratio and loading protocol on performance indices have... 

With occurring severe earthquakes, damages of columns in RC buildings can lead to overall failure and collapse. So retrofitting of such columns that do not comply with the design requirements is necessary to prevent such phenomena. A variety of methods has been introduced so far for retrofitting. The key factors in determining the retrofitting methods are being economic and easily implemented in the design. Confining concrete columns with pre-stressed steel strips is a new technique that is simple and economic. Previous experimental experiments have shown that this method can enhance ductility and overall seismic behavior of such columns.
In the present study three and six story frames... 

The purpose of this research is to study the behavior of conventional and retrofitted Khorjini connections. Thus the software ABAQUS 6.11 was used to fabricate the FEM models of the connections with experimental prototypes. In analytical studies, 21 specimens with different size of the connection components were analyzed. True stress–strain curves for steel and weld materials were used and damage initiation and revolution were considered in the weld material. Also cracking of the welds were considered by a micromechanical method. Behavioral characteristics of the conventional connections are specified and appropriate relations are suggested, using Stability equations of the connection... 

In this thesis, finite element (FE) models were developed to study hysteresis behavior of pipe braces subjected to cyclic loading. Thus steel braces previously tested by other investigators are used. The results of the analysis are in good agreement with the experiments. Besides, the FE analysis could also simulate both the overall and local buckling. As a result, a sharp growth in plastic strains is followed by geometric changes at the mid-span due to local buckling. The sharp growth of plastic strains is entitled as strain rises. In fact, the local buckling triggers rupture of braces at the mid-span. The local buckling initiation is identified by the sharp growth in plastic strains.... 

In this Thesis, the behaviour of stell brace was studied in finite element models. In this section, a comparison between the results of these models and the results of experimental models which were done in past years, was carried out. It shows that these result is in good agreement with each other, Moreover it has been found that the primary cause of failure in the sample is local bucking and then change in the geometry of sample which will be followed by strain jumping in next cycles which shows the importance of local buckling due to the proximity of this event to strain jumps and can be accepted as braces limit state design.Finally, we try to predict the time of failure of samples with... 

Masonry infills are vastly used as surrounding walls and partitions. Presence of infill in a building causes some change in strength, stiffness, period and generally seismic behavior of the structure.Mainly there are 5 modes of failure including 1- interface cracking 2- sliding along bed joint 3- diagonal cracking 4- corner crushing and 5- ultimate failure. According to these failures, three stages of strength as shear strength, corner strength and ultimate strength can be defined.Diagonal crack can be calculated by slip surface method grown in Sharif university of Technology. Based on this method the strength of infill wall falls down as the cohesive strength of mortar loses and so the slip...