JOURNAL OF FACULTY OF ENGINEERING (UNIVERSITY OF TABRIZ)
Year:2008 | Volume:36 | Issue:3 (52) CIVIL ENGINEERING|Papers Count:11

Plates arrangement around of top plate buttress connections or side plate buttress connections cause of that panel zone, connection elements and column do not fail or damage and plastic hinge developes in beam. Sampels of such connection are tested at University of Berkely [I]. In this research connections are modeled using finite element method and calibrated with experimental results. Buttress connection with side plates is modelled and investigated in this research. The effect of plates and behavior of the connections are studied using finite element modeling. The results show that in buttress connection with top plate, integrated of top plate, beam, column web stiffener plates and the dominance of the axial force in them behave in the form of a truss and create a rigid region in the connection. Removing of top plate causes panel zone falls 18 percent into plasticity and removing web stiffener of beam causes plastic hinge develops in connection area and panel zone falls 9 percent into plasticity. In buttress connection with side plates an appropriate behavior is observed due to combination of rigid bending stiffness of side plate and column web stiffener. If the bending stiffness is reduced, panel zone falls into plasticity. Using plates at top or bottom of connection causes Plastic strain at edge of beam flange and side plate connection is decreased more than 75 percent.

Near all of the soil structures built to prevent permeation are exposed to brine. In such situations, hydraulic conductivity is the most significant parameter that may be influenced. Compacted clay is the major material that is used for its low conductivity. In this study, a series of flexible wall tests have been performed on a clayey soil for different confining pressures to evaluate the effects of sodium chloride solutions on variation of hydraulic conductivity. Measurement of some properties of effluent collected fluid such as electrical conductivity, have been assisted to interpret the results. Results show that the permeation of salt into sodium montmorillonite clay increases the permeability of such soils. However the increase in the confining pressure can reduce the range of permeability of soils.

Researchers attended selection of useful sections for compressive load in examining of bearing capacity of columns. Structural engineers and architectures investigate light column sections in steel structures to get more economy. In this paper is studied cross castellated columns, in which is included accessibility of higher gyration radius with lesser material consumption and higher strength per weight of material. Column buckling capacity under axial load is dependent to the relation of slenderness (kl/r). On the other hand post buckling behavior of compression members is important to predict bearing capacity and total structural behavior. Therefore, it is necessary to specify their behavior until critical stage, including post buckling response, which is investigated here with material and geometric nonlinear analysis. In this paper, buckling behavior and ultimate capacity of built up castellated compound columns are investigated using ANSYS software. A brief of results is reported on for a number of CPE sections in different boundary conditions. Also is presented slenderness-load curve by using of Jandel software, which is a useful tool for investigation of ultimate capacity of the columns.

Reinforced earth seawalls are very useful structures to protect and stabilize the shoreline. These structures are also used as quay walls to provide adequate water depth for ship and boat berthing. Free vibration of the wall due to wave impact results in the change of tensile forces in reinforcing members and consequently affects the safety factor of the wall against collapse. So investigation of wave load induced effects on the tensile forces produced in reinforcing members is indispensable. In the present paper, the effects of breaking waves having different periods on the tensile forces produced in steel reinforcing ties of a vertical and smooth reinforced earth seawall are studied. Minikin equations are used to calculate pressures in front of the seawall. Ties are arranged as eight horizontal layers and are divided into four spans. The results showed that there is a critical wave period which leads to maximum increment in tensile force of the ties due to the wave impulse. Amount of this increment is measured for different layers and spans and is expressed as the dynamic load factor. Finally a dynamic load factor is proposed for the considered seawall in order to be used for design purposes.

Nowadays, concrete precast structures has found a particular situation in building industry. One of the resisting systems against seismic loading in these buildings is steel bracing with direct connections predicated advance. The force reduction factor is a coefficient that contains inelastic behaviour and shows hidden resistance and ductility of structures in the inelastic zone. With attention of behaviour factor in structural seismic design seems the determination of this factor is necessary. The aim of this research is to determine of force reduction factor for the precast concrete frames braced by steel elements. For this purpose, the precast concrete frames with three bays have been used. The bays width is equal to 6 meters and the story height is equal to 3 meters.Some parameters like the number of stories (4, 8, 12 stories), the rigidity percentage of frame precast connection of beam to column (0, 25, 50, 75, and 100%), the number of braced bays (1 or 2 bays), the position of braced bays, the effective stiffness coefficient for the reinforced concrete members, the lateral load pattern, effects of eccentric bracing, and evaluation of 3-dimensional frames on the reduction factor have been investigated (the rigidity percentage of zero stands for hinge connection, and rigidity percentage of 100% stands for rigid connections and rigidity percentages of 25, 50, and 75% stands for semi rigid connections). To receive this goal, the static pushover analyses have been used.