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Behbahani H., Mohammad Elahi S.,
Volume 1, Issue 1 (9-2003)
Abstract

This Paper is the result of a research project on a pavement management system that was performed by the Transportation Division of Iran University of Science and Technology. Information used in the project was gathered from 20 zones of the Tehran Municipality. Any maintenance and repair system for roads has a number of general and coordinated activities in conjunction with programming, designing, construction, Maintenance, Evaluation, and research on road pavement. Prediction of pavement condition is one of the most important parts of, such system. Prediction models have their application at the network level as well as project level activities. At the network level it is used in predicting the condition for budget programming. While in project level it is used in economical analysis. Many factors have been used in determination of pavement condition. These factors are the design life of the pavement, loading, climatic condition, and the type of road. To be able to plan for future improvements we need to predict the future condition of the pavement. In this paper, factors affecting the prediction of pavement condition are discussed. A model is developed exclusively for Tehran based on the distress data collected.
Afshar A., Marino M.a., Jalali M.r.,
Volume 1, Issue 1 (9-2003)
Abstract

The reliable operation of spillways, in emergency as well as normal conditions, is one of the vital components in dam safety. Free or uncontrolled overflow spillways are the most reliable choice however. They usually impose higher construction cost and /or results in wasting a considerable amount of water or live capacity of the reservoirs. Employing fuse gates might be a way of reconciling dam safety with maximized storage capacity. The operation of the system can be controlled to within a few centimeters, and the entire installation is not lost for floods less than the maximum design flood. The installation offers more or less the same level of safety as ungated spillways, but avoids their inherent storage capacity loss. Optimum design of fuse gates in particular installation calls for a mathematical model. The model developed in this work includes structural, hydraulics and operational constraints while maximizing the expected cost over the useful life of the project. Accounting for the lost benefit (i.e., water lost as a result of gate tilting) has an influenced effect on the optimum design. To test the performance of the model, data from Zarineh Rud dam in Iran has been used and its result is compared with a direct search technique. The model is capable of helping the design engineer to select the best alternative considering different types of constraints.
Misaghi F., Mohammadi K., Mousavizadeh M.h.,
Volume 1, Issue 1 (9-2003)
Abstract

In the present paper, ANN is used to predict the tidal level fluctuations, which is an important parameter in maritime areas. A time lagged recurrent network (TLRN) was used to train the ANN model. In this kind of networks, the problem is representation of the information in time instead of the information among the input patterns, as in the regular ANN models. Two sets of data were used to test the proposed model. San Francisco Bay tidal levels were used to test the performance of the model as a predictive tool. The second set of data was collected in Gouatr Bay in southeast of Iran. This data set was used to show the ability of the ANN model in predicting and completing of data in a station, which has a short period of records. Different model structures were used and compared with each other. In addition, an ARMA model was used to simulate time series data to compare the results with the ANN forecasts. Results proved that ANN can be used effectively in this field and satisfactory accuracy was found for the two examples. Based on this study, an operational real time environment could be achieved when using a trained forecasting neural network.
Afshar M.h.,
Volume 1, Issue 1 (9-2003)
Abstract

In this paper the analysis of the pipe networks is formulated as a nonlinear unconstrained optimization problem and solved by a general purpose optimization tool. The formulation is based on the minimization of the total potential energy of the network with respect to the nodal heads. An analogy with the analysis of the skeletal structures is used to derive tire formulation. The proposed formulation owes its significance for use in pipe network optimization algorithms. The ability and versatility of the method to simulate different pipe networks are numerically tested and the accuracy of the results is compared with direct network algorithms.
Afandizadeh Sh.,, Zoghi H. ,
Volume 1, Issue 2 (12-2003)
Abstract

Since Road transportation accounts for a large portion of total displaced passengers of Different types it is the most important mode of passenger services in Iran. The costs considered are depreciation, investment, insurance, tax, fuel, tires, main repairs, unexpected repairs, oil filter break shoe. Lubrication, batteries, commission, wages and other miscellaneous costs. These are classified into two categories of fixed and variable costs that it-ere analyzed. The data used is obtained, from the Iranian passenger transportation co- operatives based on their real costs in Fear 2002 . The methodology of determination rate of return and Passenger Transportation Price are described and these parameters are calculated. In this paper, a price model based on the economic techniques and sensitlvtfx. Analysis is presented for operators and managers. Pricing model of passenger service is prepared by the authors by the name of Development of Pricing Model of passenger Services in Intercity Roads . This research is pointing to Model Sensivity Analysis Dependent on Various Indicators.
Asghari K.,
Volume 1, Issue 2 (12-2003)
Abstract

The solution of shallow-water equation for a two-dimensional .simulation of overland /low for an actual watershed, is presented. The Petorv-Galerkin weighted residual method is used to overcome spurious oscillations inflow depth. For modeling overland flow over complex topography and variable surface, ct pre and postprocessor was developed to utilize the Triangulated Irregular Network (TIN) model and to generate finite element mesh. Close agreement of the model with measured data is obtained. This model can be used to better analyze the influence of varying surface roughness and topography on overland flow characteristics, including distribution of flow depth and velocity (is well as resulting hydrographs. Detailed spatial and temporal output parameters provide a basis fur further study of the patterns of soil erosion and evaluation of runoff natural slopes.
A.r. Khaloo, Molaee A.,
Volume 1, Issue 2 (12-2003)
Abstract

An experimental program was carried out to investigate the behavior of steel, fiber reinforced concrete (SFRC) under abrasion and cycles of freeze and them. Compression and flexural tests were also performed in order to reach a comprehensive conclusion of the response. In total, over 200 specimens were tested The test variables included two concrete strength., (i. e., 28 MPa as Normal Strength (NSFRC) and 42 MPa as Medium Strength (MSFRC)), four volumetric percentage of fibers (i.e., 0%, 0,5%, 1.0% and 1.5%) and two fiber lengths (i.e.. 25mm and 35rnrn).Cube specimens were tested according to ASTM C6661n-ocedrrre B using 100 cycles of freeze and thaw. The Los Angeles test method for testing aggregate was used to evaluate the abrasion resistance of SFRC.Test results of1VSFRCptesertted improvements up to 39% and 32 % in cylindrical and cubic compressive strength, respectively. and 88�o in modulus of rupture, 57% in resistance against abrasion based oil weight loss and 40% against compressive strength reduction due to freeze and thaw cycles. The corresponding improvements for MSFRC were 18%, 16%, 48%, 53% and 46% respectively.Increase in cocncrete strength from 28 Ala to 42 MPa provided higher freeze and thaw and abrasion resistance than addition of 1.5% of steel fibers to the normal strength concrete matrix.
Asghari K.,
Volume 1, Issue 2 (12-2003)
Abstract

The solution of shallow-water equation for a two-dimensional .simulation of overland /low for an actual watershed, is presented. The Petorv-Galerkin weighted residual method is used to overcome spurious oscillations inflow depth. For modeling overland flow over complex topography and variable surface, ct pre and postprocessor was developed to utilize the Triangulated Irregular Network (TIN) model and to generate finite element mesh. Close agreement of the model with measured data is obtained. This model can be used to better analyze the influence of varying surface roughness and topography on overland flow characteristics, including distribution of flow depth and velocity (is well as resulting hydrographs. Detailed spatial and temporal output parameters provide a basis fur further study of the patterns of soil erosion and evaluation of runoff natural slopes.
Afshar M.h.,
Volume 1, Issue 2 (12-2003)
Abstract

A least squares finite element method for the .solution of steady incompressible Navier Stokes equations is presented. The Navier-.Stocks equation is first recast into a system of first order partial differential equations with the velocitv. pressure and the vorticity as the main variables. Finite element discretization of the domain introduces a residual in the governing equation which is subsequently minimized in a least squares sense. The method so developed clearly. falls into the minimization category card hence circumventing the L.B.B. condition. Furthermore. the method produces symmetric positive definite matrices which makes the way for using more efficient iterative sobers. A Conjugate Gradient algorithm is, therefore, used for the solution of the resulting .system of linear algebraic equations. To improve the efficiency , of this iterative solver an incomplete Cholesky factorization of the stiffness matrix is used as ct pre-conditioner. Since the storage requirement of the Cholesky factor depends on the bandwidth of matrix. an effective algorithm for the reduction of this bandwidth has also been employed. The application of the method to solve cavity problem and .step flow with different Remolds number is presented to show the applicability of the method to solve practical flows of incompressible fluid The use of both linear and quadratic elements with selective reduced integration is also investigated and the results are presented.
Shooshpasha I.,
Volume 1, Issue 2 (12-2003)
Abstract

This study was designed to investigate the local volume changes induced by swelling pressure in unsaturated stand-bentonite bused buffer material. A laboratory mixture of sodium bentonite (lilt/ well graded silica stool in equal proportion by do weight was used for moisture floss experiments in both ambient and elevated temperatures. Experimental results have shown that tit high water content locations within the tested specimens, the density was reduced by .3.57% from its initial values clue to swelling. The swelling pressure was calculated by 4 different models as a function of distance. The calculated results have indicated that the density distribution within the .specimen is affected by swelling potential distribution. The calculated swelling pressure values van as u function of water content, reaching I MPa at the source of water intake, i.e., at high water content :.one, and 2 MPa cot the heater .side, i.e., cot low water content .one.
Mazloom M., Ramezanian Pour A.a.,
Volume 2, Issue 1 (3-2004)
Abstract

This paper presents the long-term deformations of reinforced high-strength concrete columns subjected to constant sustained axial forces. The objective of the study was to investigate the effects of binder systems containing different levels of silica fume on time-dependent behaviour of high-strength concrete columns. The experimental part of the work focused on concrete mixes having a fixed water/binder ratio of 0.35 and a constant total binder content of 500 kg/m3. The percentages of silica fume that replaced cement in this research were: 0%, 6%, 8%, 10% and 15%. The mechanical properties evaluated in the laboratory were: compressive strength secant modulus of elasticity strain due to creep and shrinkage. The theoretical part of the work is about stress redistribution between concrete and steel reinforcement as a result of time-dependent behaviour of concrete. The technique used for including creep in the analysis of reinforced concrete columns was age-adjusted effective modulus method. The results of this research indicate that as the proportion of silica fume increased, the short-term mechanical properties of concrete such as 28-day compressive strength and secant modulus improved. Also the percentages of silica fume replacement did not have a significant influence on total shrinkage however, the autogenous shrinkage of concrete increased as the amount of silica fume increased. Moreover, the basic creep of concrete decreased at higher silica fume replacement levels. Drying creep (total creep - basic creep) was negligible in this investigation. The results of the theoretical part of this researchindicate that as the proportion of silica fume increased, the gradual transfer of load from the concrete to the reinforcement decreased and also the effect of steel bars in lowering the concrete deformation reduced. Moreover, the total strain of concrete columns decreased at higher silicafume replacement levels.
Kheyr Aldin A., Mortezaei A.r.,
Volume 2, Issue 1 (3-2004)
Abstract

Structural walls are used extensively in moderate- and high-rise buildings to resist lateral loads induced by earthquakes. The seismic performance of many buildings is, therefore, closely linked to the behavior of the reinforced concrete walls. The analytical models used in this paper are developed to study the push-over response of T-shaped reinforced concrete walls andinvestigate the influence of the flange walls on laterally loaded walls and nonlinear behavior of shear walls, namely strength, ductility and failure mechanisms. A layered nonlinear finite element method is used to study the behavior of T-shaped and rectangular (barbell) shear walls. This paper introduces a computer program to practically study three-dimensional characteristics of reinforced concrete wall response by utilizing layered modeling. The program is first verified bysimulated and reported experimental response of 3-D reinforced concrete shear walls. Subsequently, a study considering eighteen analytical test specimens of T-shaped and barbell shear walls is carried out. Finally, based on analytical results, a new equation for minimum ratio of shear wall area to floor-plan area is proposed.
A. Ardeshir,
Volume 2, Issue 1 (3-2004)
Abstract

In this research a mathematical model was developed to study bed elevation variation of alluvial rivers. It utilizes two principal modules of hydraulics and sediment transport for simulation purposes. SDAR (Scour and Deposition model of Alluvial Rivers) is a new model with both one and semi-two dimensional (S-2D) computational schemes. It is regarded S-2D in a sence that lateral variation of velocity, hydraulic stresses, and geometrical specifications are achieved by dividing the main channel into serveral stream tubes. In order to overcome the existing limitations, a new idea of reachwise stream tube concept was also introduced. This allows to include branch connections and withdrawal points across the tube barriers. Sediment routing and bed variation calculations are accomplished along each river strip desigated by virtual interfaces of the tubes. Presently, quasi-steady gradually varied flows are processed by the model. It should also be emphasised that this version is only valid for alluvial rivers composed of noncohesive bed material. To assess the model, several river cases and laboratory data base were used. During calibration runs, the ability of model in longitudinal and transversal bed profile simulation and armor layer development predection were especially detected. Results of simulation are also compared with the results of well-known models, e.g. HEC-6, GSTARS-2, and FLUVIAL-I2. It was found that the ability of model in simulating bed variation is noticeably increased when S-2D concept is introduced. Indeed, the comparative validity tests confirm SDAR"s promising functioning in facing with complex real engineering cases. Obviously more article discussions would bring oppurtunities to demonestrate it"s technical cappabilities profoundaly.
Khaki A.m., Moayedfar R.,
Volume 2, Issue 2 (6-2004)
Abstract

The purpose of the present study, is proposing a more flexible model comparing with linear regression model, to estimate the rate of household trip production and its prediction in the�project horizon. For this purpose, a combined model composed of poission distribution and the possible distribution of A. in the form of negative binominal distribution are used. Then the proposed model was conducted on a real case (Karaj City). Then the result of model processinghas been compared to .the real observation in the peak hours in Karaj city.
Saffar Zadeh M., Asadi M.b.,
Volume 2, Issue 2 (6-2004)
Abstract

In this research, the Integrated Noise Model (INM), has been calibrated to perform the noise pollution evaluation in the vicinity of Mehrabad International Airport (MIA). First a conceptual model was developed to analyze the compatibility of airport noise with the land use based on the most widely accepted noise pollution standards. Second, the data generated from the INM package was compared with real data acquired from the test stations positioned around airport. Finally, the outputs of the calibrated model was compared with the noise pollution standards. The results show that more than 70 percent of the land use in the vicinity of airport are not compatible with the accepted noise levels. The generated noise contours was superimposed on the digital map of the city and the areas which violated the permitted levels was recognized. Moreover, the more noise sensitive facilities such as hospitals, schools, and residential units can be positioned in areas which have the permitted noise levels. The model and the procedure can be used to design new airports. Noise evaluation of existing operational airports can be performed by the model developed in this research.
Ayati E.,
Volume 2, Issue 2 (6-2004)
Abstract

Government agencies and the medical, insurance and automotive industries all have an interest in understanding the socio-economic costs of road crashes. These costs are estimated in most countries, and their computation methodology are continuously progressing as more refined costing methods, are used. This paper outlines two recent studies in Iran and Australia in order to compare crash cost estimation approaches. The analytical approaches and the results of similar studies in some other countries are also discussed It is shown that different approaches to estimating human costs and its components have considerable effects on the results. In both studies, the contribution to the total costs are human costs (50 to 60 percent), vehicle costs (30 percent) with the remaining 10 to 20 percent covering general costs.
Kimiaei M., Shayanfar M.a., Hesham Ei Naggar M., Agha Kouchak A.a.,
Volume 2, Issue 2 (6-2004)
Abstract

The seismic response of pile-supported offshore structures is strongly affected by the nonlinear behavior of the supporting piles. Nonlinear response of piles is the most important source of potentially nonlinear dynamic response of offshore platforms due to earthquake excitations. It is often necessary to perform dynamic analysis of offshore platforms that accountsfor soil nonlinearity, discontinuity condition at pile soil interfaces, energy dissipation through soil radiation damping and structural non linear behaviors of piles.In this paper, an attempt is made to develop an inexpensive and practical procedure compatible with readily available structural analysis software for estimating the lateral response of flexible piles embedded in layered soil deposits subjected to seismic loading. In the proposed model a BNWF (Beam on Nonlinear Winkler Foundation) approach is used consisting of simple nonlinear springs, dash pots and contact elements. Gapping and caving-in conditions at the pile-soil interfaces are also considered using special interface elements. This model was incorporated into a Finite Element program (ANSYS), which was used to compute the response of laterally excited piles. A linear approach was used for seismic free field ground motion analysis. The computed responses compared well with the Centrifuge test results.This paper deals with the effects of free field ground motion analysis on seismic non linear behavior of embedded piles. Different parts of a BNWF (Beam on Nonlinear Winkler Foundation) model, together with quantitative and qualitative findings and conclusions for dynamic nonlinear response of offshore piles, are discussed and addressed in detail. The proposed BNWF model (only using the existing features of the available general finite element software) could easily be implemented in a more comprehensive model of nonlinear seismic response analysis of pile supported offshore platforms.
Afandi Zadeh Sh., Zoghi H.,
Volume 2, Issue 2 (6-2004)
Abstract

Since Road transportation accounts for a large portion of total displaced passengers of Different types it is the most important mode of passenger services in Iran.The costs considered are depreciation, investment, insurance, tax, fuel, tires, main repairs, unexpected repairs, oil filter break shoe. Lubrication, batteries, commission, wages and other miscellaneous costs.These are classified into two categories of fixed and variable costs that it-ere analyzed. The data used is obtained, from the Iranian passenger transportation co- operatives based on their real costs in Fear 2002 .The methodology of determination rate of return and Passenger Transportation Price are described and these parameters are calculated. In this paper, a price model based on the economic techniques and sensitlvtfx. Analysis is presented for operators and managers.Pricing model of passenger service is prepared by the authors by the name of Development of Pricing Model of passenger Services in Intercity Roads . This research is pointing to Model Sensivity Analysis Dependent on Various Indicators.
Mohammad T. Dastorani, Nigel G. Wright,
Volume 2, Issue 3 (9-2004)
Abstract

In this study, an artificial neural networks (ANN) was used to optimise the results obtained from a hydrodynamic model of river flow prediction. The study area is Reynolds Creek Experimental Watershed in southwest Idaho, USA. First a hydrodynamic model was constructed to predict flow at the outlet using time series data from upstream gauging sites as boundary conditions. The model, then was replaced with an ANN model using the same inputs. Finally a hybrid model was employed in which the error of the hydrodynamic model is predicted using an ANN model to optimise the outputs. Simulations were carried out for two different conditions (with and without data from a recently suspended gauging site) to evaluate the effect of this suspension in hydrodynamic, ANN and the hybrid model. Using ANN in this way, the error produced by the hydrodynamic model was predicted and thereby, the results of the model were improved.
F. Eftekharzadeh,
Volume 2, Issue 3 (9-2004)
Abstract

According to experiences, zones of weaknesses, joint systems and sliding surfaces in rock masses, have a great effect on the deformation behavior of tunnel cross section and the stress development in the shotcrete cover. The loosening and detaching of rock due to roof deformations in turn can take progressive dimensions and lead to roof fall and in extreme case cave to the surface. In this study, the effect of weakness zones on increasing roof deformations is demonstrated and the radius of influence of such weaknesses is determined using a FE- program for 3- dimensional continuum. Furthermore it is shown that the thickness of such disturbances does not significantly affect the development of deformations i.e. if the stiffness conditions remain constant. Also the viscous material causes greater deformations than the elastic one. Finally the study indicates that tangential stresses in the lining are also increased by weakness zones.

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