JOURNAL OF FACULTY OF ENGINEERING (UNIVERSITY OF TABRIZ)
Year:2004 | Volume:30 | Issue:3 (36) Civil Engineering|Papers Count:7

In this study, using the laboratory models, the contaminant transport from a landfill to a groundwater was modeled using two-layer soil system. The models consist of a clay and a sand layers and a receptor reservoir. During the tests the concentration of chloride in source and receptor reservoirs was observed. At the end of the test, soil sample was sliced and the concentration was determined in soil depths. The observed data was accurately predicated by the computer code POLLUTE. In the three first tests water flow was downward and advection and diffusion were at one direction. At the two other tests water flow was upward and advection was opposite of diffusion. Comparison of the results at the later tests, which modeled the natural hydraulic trap system, with the results of the first three tests, showed that the hydraulic trap system has reduced the contamination in the receptor reservoirs and hence, this system could be implemented in the design of the solid waste landfills.      

The influence of connection strength and rigidity on the seismic performance of steel moment resisting frames is investigated. The seismic response of frames with three, eight and fifteen story is evaluated. These frames with rigid and semirigid connections were subjected to five em1hquake records. In ultimate limit state, the response of rigid and semirigid frames is compared in terms of the base shear story drift ratio, failure mechanism and behavior factor. These studies indicate that, the semirigidity of steel frames does not necessarily result in larger drift or in more damage than in rigid frames. It was also observed that, a well-proportioned semirigid connection could participate in the nonlinear behavior of the structure and enhances the dynamic performance of steel frames.      

Study of flow characteristics over cylindrical weirs is very important in design and application of such structures due to high curvature in their streamlines. In this research, flow conditions for cylindrical weirs and the effects of some factors like diameter of the weir, hydraulic head and downstream depth on the discharge coefficient for developing of its equation by experimental approaches were investigated. The tests were performed on the weirs with different diameters and flow rates. The results of tests showed that the discharge coefficient of cylindrical weirs is greater than the other broad-crested one's. It increases in a power relationship with increasing the ratio of total head in upstream to the diameter of the weir. Also the submergence threshold with 0.5 to 20 liters/second flow rates is 0.7-0.89.      

In order to investigate behavior of stochastic inflows to multiobjective reservoir a probabilistic model has been used .This model can describe river flow for the purpose of forecasting future situations. To convert chance constrained goal programming (CCGP) model to its deterministic equivalents model. OSM computer software has been developed which is written in FORTRAN 77. OSM software can extract conditional and nonconditional cumulative distribution function (COF) of inflows to reservoir and calculates inverse CDF of inflows for flood and drought control reliability by using Newton's differential interpolation method. The model is applied to the Mahabad multiobjective reservoir which is a portion of the Urmia lake watershed. This reservoir is constructed to control water for several purposes such as municipal water supply irrigation demands flood control and hydroelectric power generation. Use of this model allows the reservoir manager to rank various goals according to their relative impol1ance.      

Nowadays, usage of heavy industrial machines has been increased rapidly and special knowledge for geotechnical engineers is required for convenient design of machine foundations. In this paper conventional methods for analysis of machine foundations have been studied. All of these approaches assume that soil behavior is elastic and homogeneous. In addition most of these methods neglect shape of foundation. In this paper, ANSYS 5.4 is used for better analysis of machine foundation. Using this powerful software, a new model is proposed that can consider both soil and foundation behavior together. Applying this model, determination of foundation displacement is possible. Also, foundation settlement located on the multi-layered soils, embedded foundation and effect of foundation shape on the behavior of foundation under dynamic loads can be studied. Finally results of proposed model have been compared with that of conventional method.    

Transport of bed material downstream of hydraulic structures as control gates can be found in case of erosion or scour that has significant effect on hydraulic structures and finally damage them Theories that exist on sediment transport were based on critical velocity, energy of flow, statistical and probability theories, dimensional aspects and so on but none of them pay attention to main subject which is indeed distribution of velocity, volume and momentum and energy flux. This paper pronounced local scour due to two dimensional submerged wall jets and correlation of incipient motion caused by fluid power of jet.    

The objective of this study is to define an index for ranking the provinces (states) of our country in terms of transportation facilities. This index which is aimed to represent the potential of transportation facilities in each province, is a dimensionless number .By the potential of transportation facilities we mean factors such as length of highways and railways, number of airports and harbors , the population of vehicles, the tonnage of goods and number of passengers. A mathematical approach rather than a statistical one is suggested this index, as the transportation industry is very vast with different variations, and presentation of mere statistical figures would not be helpful .In this regards, three indices are presented, which are hoped to assist the government, investors and the planners in evaluating the transportation facilities of the provinces for their planning purposes.