JOURNAL OF TRANSPORTATION RESEARCH
Year:2019 | Volume:16 | Issue:3 (60) |Papers Count:17

Correction old OD matrix is one of the Cheapest methods for provide the Origin-destination matrix for the base year, which are based on the observed values in selected links. In each of these methods, in order to obtain the share of each links from the demand between the ODs, the primary matrix (and in subsequent replicates, the modified matrix) is assigned to the network. By introduction of fuzzy concept, new methods for correcting the OD matrix have been refined, which called the fuzzy flow method (TFF). This method uses the matrix assignment as well as other methods in the matrix correction process. Considering the importance of the assignment method used in matrix correction, this paper deals with the effect of traffic assignment method in traffic fuzzy flow correction method. The results show that the use of the user equilibrium method is superior to the stochastic and incremental assignment, and the good fit coefficient in the user equilibrium method is equal to 0. 82, while in the stochastic method, this R2 is 0. 72 and in the incremental assignment has a value of 0. 67.

Nowadays, with increasing population and the severe shortage of space, the general preference is to construct buildings with deep and semi-deep excavations. However, changing the material from a soil to the rock, the stability conditions and its analysis are noticeably affected. In a rock slopes, there are weak levels with different direction and density which form different patterns of failure. In this paper, the case study on the static and dynamic stability of the rock slope caused by excavation up to the depth of 15meters have been investigated with considering the structural anisotropy effects due to the presence of stone joints, blocks and the pore water pressure. The main challenge is the existence of rocky jointed materials with water seepage through them. In order to collect data for some single joints, the structural geology analysis has been carried out by using the Streo net grid strategy in DIPS and statistical software. Finally, static, dynamic and hydrostatic analysis has performed using UDEC software based on discrete element method. The results show that the rock slope in the static and dynamic state of stability has been unstable due to the application of hydraulic flow.

The level of safety of transportation being low often considers an obstacle to sustainable development. Pedestrian safety is one of the essential problems, researchers of the safety of transportation face. Since non-signalized intersections lack the controllers of safety and have many conflicts between pedestrians and vehicles, are considered to be a dangerous place for pedestrians. The conflict between pedestrians and motorcycles and the variables which influence those conflicts are the issues that are not paid enough attention by researchers. The data used in this paper have been achieved using the image processing method. The effects of the variables related to the pedestrians and the motorcycles on Time to Collision (TTC) have been estimated using a linear regression model. The intersection assessed in this article is located where Vesal-Shirazi (the major street) and Bozorgmehr(the minor street) street meet together. Finally, in the reliability of 95 percent, the variables such as the direction of the pedestrian movement, the pedestrians moving in a group and the direction of motorcycle movement significantly influenced TTC with the numbers-0. 22, 0. 28, and-0. 32 respectively.

In this study, the effects of two typical commercial heavy airplanes, namely airbus AA380-800 and Boeing B747-400ER, on the potential of reflective crack propagation in composite pavement have been investigated. The axles of the airplanes were positioned at different longitudinal and transverse distances from the center of crack and the stress intensity factors, and tensile strain at the tip of crack in asphaltic layer were determined and compared. Modeling and analysis were performed using extended 3D finite elements method. The asphaltic layer was assumed to behave as a viscoelastic material and the underlying layers were assumed to be linear elastic. Results show that higher maximum stress intensity factor in mode 1 is generated under Boeing airplane loading than airbus, and those in mode 2 and 3, are higher for airbus than Boeing. Results also reveal that by moving the center of axles along the longitudinal joint, the maximum tensile strain at the tip of crack decreases, such that 42. 87% reduction for airbus and 23. 89% reduction for Boeing airplane is obtained, in comparison to the loading at the center. By moving the center of axles in transverse direction, the maximum tensile strain at the tip of crack increases by 26. 73 and 17. 93%, in comparison with the load at the center for airbus and Boeing airplane, respectively.

Fatigue is one of the most effective parameters on the life cycle of the railway slab track. In this paper, a simple method is developed to estimate the life cycle of railway slab track based on the concrete fatigue. For this purpose, a mathematical/analytical model consists of two layered beams laid on elastic foundation is used to calculate the time history of stress induced in the concrete slab. Rain-flow counting method was used to count the stress cycles of the obtained time history. Finally, the life cycle of railway concrete slab track has been calculated according to the tensile fatigue behavior of concrete and stress cycles. The results obtained in this research indicate that as thickness of concrete slab and 28 days compressive strength of the concrete are increased, the life cycle of concrete slab track is increased. When the subgrade stiffness of concrete slab is increased, the life cycle of slab track is raised negligibly. Moreover, when the traffic volume passed over the track is increased, the life cycle of slab track is decreased dramatically.

In today's competitive world and trying to produce more and earn maximum profit in mining industry, analyzing the behavior of the fleet system is more important. Information available on the failure rate and repair time of system components is uncertain and imprecise so it is difficult reliability analyzing and prediction behavior of system based them. In the present research, behavior and reliability analysis of shovel System as an important equipment fleet of transport in open pit mine investigated under uncertainty using by fuzzy set theory and lambda-tau methodology. Cable shovel consists of seven subsystems (cable, bucket, stick, under carriage, engine and gearbox, pneumatic and electrical) in a series network configuration that have Weibull distribution for failure time. Behavior of system is analyzed by using various reliability indices namely reliability, availability, MTBF (mean time between failures), failure rate and repair time. Results show that failure information has uncertainty less than repair times; and after 10 hours, RAM-index of system decrease. Behavior system analysis as helpful tool for select suitable maintenance strategy and improve performance system can be used.

Traffic operations in the congestion parts of road networks are very complicated and a comprehensive analysis of interactions between vehicles is essential for understanding the bottleneck event and providing solutions for addressing the issues. This involves the development of traffic theories to explain driver behavior on the microscopic state, that one of its main elements is lane changing behavior. In this research, the effects of vehicles lane changing before the right turn for exiting from the intersection and after the right turn for merging into the next urban corridors, in different percentages of the right turn traffic volume in the three well-known intersections namely "Felezi-Mellat", Simin, and Sadoogh " intersections in Isfahan city, one of the most congested city in central part of Iran, using Aimsun software were studied and evaluated. The data collection method was done using videotaping technic and peak hour of the intersections was recorded. Then the geometric and traffic characteristics of the intersections were extracted using field observations data extraction from the recorded films. For the aim of the research, two main parameters of the Aimsun lane-changing model, including distance zone 1 and distance zone 2, were estimated with proposed values. In the end, using Synchro software, signalized intersections timing were optimized under different scenarios. Having used the proposed timing schemes, the intersections were modeled in Aimsun software in order to evaluate the traffic measure of effectiveness under defined scenarios. The results showed that using the proposed values instead of the default values of Aimsun lane-changing model changed the value of travel time in the aforementioned intersections of the Felezi-Mellat, Simin and Sadoogh by (1) to (-9), (0) to (-15), and (0) to (-5) percent, respectively.

Global logistics includes transportation in land and sea side. In land, trains and trucks are used to transport goods. The design of the transportation network and connection between land and sea includes determining the location of distribution centers and their connections with the maritime ports. Determining the optimal location and capacity of distribution centers and type of transportation means for the delivery of goods between sea ports, distribution centers and customer nodes, has a high importance in the distribution network's efficiency. In this research, a two-objective math programming model is proposed for locating distribution centers in which multimodal transport is used to connect the port and hinterland. In this model, the internal and external supply and demand flows of each node are intended to determine the location of distribution centers or terminals in hinterland, with the aim of minimizing the transport costs as and pollution caused by vehicles. In this study, the modified Epsilon method has been used to solve the problem. The results of the research showed that the construction of distribution centers and the development of transportation modes should be in the range of 96 to 106 billion dollars. Also, the amount of carbon dioxide produced in each of these investments will be about 40 to 56 million tons a year.

Diversity of housing is one of the key elements of contemporary urban planning that due to its social, economic and environmental benefits, it is welcomed and emphasized by modern urban sustainable development models (such as the urbanization movement and smart urban growth) is located. However, in the urban planning system of Iran, this principle has not received much attention, and such a decline has not only reduced the level of urban viability but has also contributed to their instability on a larger scale. Since the dimensions of this issue have not been properly identified in the urban planning studies of Iran so this article aims to investigate and deepen the concept of urban housing on the one hand and to identify its effects on the selection of urban trips according to the neighborhood sample. The Qom Foundation has been written. The research method used in this study is descriptive-analytical and the required information was collected through field surveys, questionnaires, and so on. The results of this study show that low level of housing diversity in Bonyad neighborhood caused 44% of residents to move by personal car, 33. 6% by walking, 13. 8% by riding and 7. 2% by car. Public transportation and 1. 7% of other modes are shifting, in other words, these have increased residents' out-of-town trips, transportation costs and energy consumption, and in short, the livelihoods and sustainability of these areas have increased. Such an issue is strongly overshadowed, which suggests that the main precondition for creating sustainable housing environments is to diversify housing construction patterns.

The Islamic Republic of Iran, due to its connection with free seas, has a great importance for the transit of goods. Pathology of the Present Status of Multimodal Transit and its Strategies for Success in Iran, are the main goals of this research. In this research, using grounded theory and deep interview methods, identifying the factors affecting the success of multimodal transit in Iran and it has been studied the Iranian transit systems based on the above model and how to improve it. The statistical community is composed of experts in transportation and transit of goods, traders and Merchants and analysis of information, done with MAXQDA software. With this research, the causes and factors of the lack of development of Iran transit in different areas were identified and classified into six categories and 32 main factors and some solutions suggested for their improvement.

Today, in the development planning process, identifying and explaining the level of awareness of strengths and weaknesses and areas of development is very important, Contact the transportation sector because, among other key sectors in the development of numerous sectors. Therefore, this study is conducted aimed at leveling the development of the criteria of road transportation. This research targeting practical and descriptive-analytic methodology in terms. Where the method is used surveys of experts and library studies. Statistical population all the cities in Khuzestan Province That of road transportation using the model parameters were evaluated PROMETHEE and GAIA analysis. ANP model is used for weighting the indices. Based on the results of 24 city of the province, two city is very enjoys city, 3 city is enjoys city, 5 cities relatively enjoys, 6 cities is inappropriate and 8 cities is quite inappropriate development. Khorramshahr city with Phi (592/0) and city Bavi with Phi (412 / 0-) in the first rank, come last. Overall, the results indicate that a wide gap between the townships terms of indicators of road transport there.

Employing different waste materials in roller compacted concrete (RCC) mixtures has fascinated investigators recently. The main interception of utilizing wastes in concrete is its engineering properties loss. As a result, using additives has been suggested to modify mechanical properties of mixes efficiently and economically. In present research, waste crumb rubber has been used for fabricating specimens and the influence of nano-silica and fly ash incorporation was assessed. Design of experiments was programed using Taguchi method and mix design was optimized accordingly. A 40 % to 70% fly ash content (by the weight of cement and replacement), 0 to 30% crumb rubber content (by the weight of fine aggregates and replacement) and 0 to 3% nano-silica content (by the weight of cement and replacement) were incorporated in the RCC mixtures. Moreover, L16 orthogonal array with a mixed-level design and signal-to-noise (S/N) of larger is the better was used for design of experiments. The Taguchi method is a proper way for mix optimization and determining precise percent of components in mix design. The main objective is RCC strength optimization based on RCC structural limitations. It is noteworthy that crumb rubber incorporation in concrete precedes mechanical loss of mixture. To gain proper mix design with great engineering properties and to obscure mechanical loss nano-silica powder was employed in mix combinations. The final results of compressive, flexural and splitting strength of mixtures tested after 28 days curing in laboratory were maximized with Taguchi method. Finally, the results reviled that the mix with 27% crumb rubber (by mix volume), 50% fly ash (by weight of cement) and 2% nano-silica (by weight of cement) incorporations, should be considered as optimal mix.

Pay factors are an integral part of the quality assurance. Since the production and supply of asphalt cannot meet all the specifications in accordance with the criteria, determining the relationship between quality and payment is important. The results of the studies on 21 Marshall mix design and 592 sheets of quality assurance and field inspections from asphalt plants show that in preparing the mixing design some cases of inaccuracy in determining the type of traffic, sampling, determining the optimum bitumen content and using The mixing plan is seen for a period of several years. In general, quality control has been low in the 12 projects examined, and there are no recommendations for general technical specifications. Marshall's experiments in this study that affect the pay factor are performed without hammer calibration and are sometimes computable mistakes. It was also found that in some of these projects, in spite of the lower percentage of Marshall parameters inside the specification, they had a higher pay factor, which could be considered And considering the reasons for the non-conformance in this research, it can determine the ineffectiveness of the selected pay factor or indicate that the use of (QA) results for acceptance and payment to the contractor, regardless of quality control (QC) Cannot be used as a way to increase the quality of asphalt pavements and to include costs based on the life cycle.