فصلنامه جاده
سال سی و دوم شماره 1 (پیاپی 118، بهار 1403)

The present paper investigated the dynamic and durability characteristics of silty-sand soil used in the base layer treated with cement and a mineral polymer via a series of laboratory tests.The specimen selection for the cyclic triaxial test was based on the results of the uniaxial compressive strength, Brazilian tensile, wetting-drying and freezing-thawing cycles tests. The results showed that, the compressive strength of the cemented soil can be reached in the shorter period of times and volume loss of the cement specimen may be eliminated due to the use of polymer. The compressive strength of the treated specimen with 6.3% cement and 0.7% polymer and has been selected as the optimal combination. In the durability test, the cement-polymer specimens show a better performance than cement specimens, and this trend is more noticeable in wetting-drying cycles than freezing-thawing cycles. In the next step, the cyclic triaxial test was performed on four optimal combinations with treated cement and cement-polymer. An increase in frequency raises the resileient modulus and damping ratio, while it has decreased the axial strain. For AASHTO T307 stress level, the mean values of the resilient modulus of cement-polymer specimen were higher than cement specimen in two curing modes. Meanwhile, for damping ratio parameter, the cement specimen show a better performance than cement-polymer specimen. Generally, soil treatment with the cement-polymer specimen demonstrated a relative advantage over the cement-only specimen in the medium stress range for the base layer in wetting-drying mode (as defined by stress levels in AASHTO T307 standard).

Bike-sharing systems are clean transportation modes that contribute to reducing traffic congestion, air pollution, and improving access to public transportation. The use of clean transportation, especially bike-sharing systems, are considered an effective solution for addressing traffic-related problems, air pollution, and improving the quality of life around the world. Unfortunately, in Iran, this mode of transportation has not been given much attention, and Low share of intra-city trips is made using bike-sharing systems. To adopt effective transportation policies in this regard, it is necessary to identify the factors affecting the choice of bike-sharing systems. In this study, the choice of using bike-sharing systems was modeled using a ordered logit model to identify the factors affecting the maximum duration for using bike-sharing systems in Tehran city. Data were collected using a questionnaire, with a total of 418 completed questionnaires, which were reduced to 400 after cleaning the data. According to the results, factors such as providing a safe environment for cycling (constructing dedicated bike lanes), air cleanliness, Road aesthetics, very low environmental gradients on the last trip, resulted in using bike-sharing systems for more than 15 minutes. Factors such as the feeling of social deprivation while riding a bike, physical weakness, lack of interest in bike-sharing systems, commuting for work purposes, resulted in not using or using bike-sharing systems for less than 15 minutes.

The purpose of this research is to investigate the impact of self-driving cars on changes in travel. To do the work, first, the data related to persons, households, land use, and skim matrices between the studied areas of Washington DC were entered into Activitysim software. The information obtained from the models without the presence of self-driving cars was examined, then the way the self-driving car traveled was added to the software, and the information resulting from the effects of these cars on the changes in trips, which is derived from the changes in the variables of the specific age group, the travel time in the accessibility, choosing more distant destinations for non-mandatory tours and the frequency of non-mandatory tours, in considered. The results in the one-dimensional analysis of the variables show that among the selected variables, the variable of non- mandatory activities of people in the frequency model of non- mandatory tours with 11.7% and the variable of travel time in accessibility model with 5.5% have the greatest effect on the changes in the number of trips. Also, the presence of self-driving cars has the greatest impact on shopping and leisure trips. Another goal of this research is to build a quick response model. After examining the interactive effect of the variables, it was found that the travel time variables and the activities of the working people, the age group under 18 years, and the retired are the most important variables influencing the changes in the number of trips.

Port operation management plays a crucial role in the shipping industry and maritime trade. Various methods and tools can be used to improve port operations management, including the application of simulation software for port operations. These software are typically used to optimize port operations, capacity assessment, container loading and unloading traffic, storage management, container location and allocation, ship scheduling, and similar tasks. Shahid Rajaee Port, as the largest and most important commercial port in Iran, is one of the most vital and densely configured ports of the country, and its operation management is very complex due to the diversity, extent and overlap of activities. The use of simulation software can play an effective role in improving operational management in this port. Empty container allocation is one of the port operations which is carried out by the South Shipping Line- Iran Line company as the operational arm of the Islamic Republic of Iran Shipping Lines Group and the main provider and responsible party for the majority of empty container operations. In this article, the process of sending empty containers to requesting terminals has been simulated using the ARENA software. The results show that by implementing management measures such as spatial distribution of empty container storage locations and asynchronous calling of trucks based on a pre-scheduled plan, the queue length and average waiting time in the queue can be reduced by up to 74% and 80% respectively.

Today, due to its high safety factor and favorable environmental pollution, rail transportation has a major contribution to the movement of cargo and passengers. The use of modern technologies such as automatic control systems in signaling, communication, and train control increases speed. The number of rail accidents has also decreased in the field of safety. Due to the country's strategic position, which is located in the center of the north-south and east-west corridors, neighboring countries with oil and gas resources are often forced to transit their oil and gas exports through Iran's railway lines. So in order to To increase safety and prevent accidents, the transportation of dangerous goods by rail should be carried out in compliance with all safety principles, such as compliance with unloading and loading rules, the selection of wagons suitable for the conditions of transportation of dangerous goods, and the labeling of wagons. In this article, railway accidents related to trains’ escapes in the world and as a case study, the accident and explosion of freight wagons at Khayyam station are investigated, and the causes and factors of such accidents are discussed, the most important of which are: performance Inadequate and defects in the braking system of trains, improper brake adjustment during the brake test process, lack of compatibility and matching of cargo in successive wagons and replacement of the locomotive. Also, guidelines for prevention and improvement of safety have been provided.

The current research, the impact of rail transport development indicators on the reduction of damages and deaths caused by road accidents during a 20-year period in 1377-99 has been evaluated. the research method and the statistical data used were first introduced, and then the generalized Augmented Dickey-Fuller test was used to check the significance of the variables. Then, to determine the long-term relationship, the Cointegrating co-accumulation test was used between the variables, and then the Granger causality test was used to determine the short-term relationship between the variables. In the last step, the residuals from Cointegrating Regression were calculated and the short-term parameters were obtained by estimating the error correction model. In the last step, the residuals from the Cointegrating regression were calculated and the short-term parameters were obtained by estimating the error correction model. The results show that there is a relationship between the variables of length of railway lines, ton-kilometers of freight transported, person-kilometers of passengers moved and added value in the rail transportation sector, with the variable of deaths in extra-urban road accidents, and this relationship is one-way. This means that with an increase of one percent in the growth of the variables of the length of railway lines and the growth of ton-kilometers of goods transportation and person-kilometers of passenger movement and added value in the rail transportation sector, we witnessed a decrease in the number of deaths in road accidents outside the country by 0.011 and 07.01 We will be 0.24 and 0.115.

Today, the proper use of waste and disposal that affects the environment around us, It has received a lot of attention, Because it is both environmentally and economically valuable to help with the environment we are in. According to that thousands of tons of steel waste is produced annually in the country's industrial community And through the collection of these wastes and their relocation to the factory and their smelting, they are again produced under steel conditions at high cost Or, because of its indivisibility, it is left unused in our environment and takes up a lot of space. Therefore reusing these wastes would be very beneficial. Research has shown that the use of iron filings in ordinary concrete has been repeatedly performed by different individuals, but in roller compacted concrete, it has not been done separately to reduce or increase resistances. This type of concrete pavement is known as the roller compacted concrete which has zero slump and is much cheaper and has a better performance than other concrete pavements. Due to the good advantages of this type of pavement over other asphalt and concrete pavements, the tendency to use this type of pavement is increasing. Therefore, the aim of this study was to investigate the effect of iron filings on the mechanical properties of roller compacted concrete in road pavement. In this research, after purchasing the aggregate, iron filing, cement and providing these materials in the laboratory, The process of screening the aggregates was performed.

One of the important goals of Iran's transportation industry, based on the vision document of rail transportation, is to reduce greenhouse gas emissions and optimally manage energy resources, according to which, in 2029, up to 35% of cargo transportation in the country should be carried out through the rail network. In this regard, the use of multimodal transportation seems obvious and useful. In this regard, promoting rail transportation as a green method against green methods such as road transportation, more than anything else, requires evaluating and providing effective optimization solutions. Therefore, in this research, an attempt has been made to provide a hybrid model to evaluate different modes of transportation and in this way to check the flow of freight transportation in the rail network. Therefore, in the present research, a random optimization model has been presented for the evaluation of freight transportation methods, so that the coefficients of the variables have a relative flexibility for optimization. To achieve the goal of stability after initial formulation, which has relative certainty, based on non-linear integer programming, a stable model has been compiled and compared with non-stable models. The challenges of robust planning, in a multimodal space, in terms of the variety of freight transportation facilities in road and rail aspects, require considering the limitations associated with the objective function, which is attempted in this research through the interaction between various types of rail network flows, a proper evaluation of the model about be provided at the expense of road-rail transportation facilities and the capacity of the rail network. Therefore, an approximate algorithm for checking and explaining deterministic alternatives in a reasonable computing time has been investigated. Stable and non-steady models are also focused on the country's rail network in this research, and it has been tried to provide a suitable and useful tool for analyzing and responding to the demand of freight transit companies in the conditions of competition with the road sector through testing the model's applications.

In response to the Covid-19 pandemic, governments around the world have imposed severe traffic restrictions and presented different scenarios to reduce emissions from traffic sources. By applying the traffic restrictions caused by the Covid-19 epidemic, it was expected to see changes in the concentrations of air pollutants. Therefore, it was decided that the changes of air pollutants as one of the subsets of the environmental index of sustainable urban development during the covid-19 epidemic will be investigated. For this purpose, the aforementioned data are first collected in the four metropolitan cities: Tehran, Karaj, Ahvaz and Tabriz, and then processed and cleaned. After that, a proposed algorithm based on machine learning methods is presented. Machine learning methods decision tree, random forest, support vector machine, Bayesian network and perceptron neural network are applied to the selected features. Investigations showed that the prediction model using decision tree and random forest had the best performance for both recall and accuracy criteria. The research results showed that the effect of restrictions on the concentration of pollutants in different cities is different. Also, the results show that, in general, the application of traffic restrictions during the epidemic period did not have a significant and noticeable effect in reducing the concentration of air pollutants. Also, by comparing the change in air quality index with the death rate during the epidemic period, it was found that there is no relationship between them.

Abrupt changing in track vertical stiffness on railway bridges transition zone, increased dynamic loads and asymmetric deformations. Using elastic pads on the deck such as under sleeper pads and rails reduce the track vertical stiffness on deck. So a finite element model of the ballasted track and short span bridge were created and validated.The results show that at method used under sleeper pads on deck , state use the under sleeper pads with variable stiffness for all sleepers on the deck is the best performance and nearly 20, 5 and 7 percent improvement in behavior in terms of static rail vertical displacement, ballast layer vertical displacement and normal stress in subgrade layer respectively and based on dynamic analysis rail dynamic vertical displacement and rail vertical acceleration improved 9 and 16 percent respectively. About combinatorial transition method include improved embankment in transition zone with resilient pads under the rail for rail on deck improved track behavior based on the criteria the rail vertical displacement and ballasted layer vertical displacement about 31 percent, also decreased the normal stress in the middle of the subgrade layer approximately 24 percent and based on dynamic analysis, rail dynamic vertical displacement and rail vertical acceleration is improved by about 27, 34 percent respectively.

Nowadays, if the changes of the influencing factors of construction in construction projects are properly managed and paid attention to, most of these factors can be directed towards achieving the project goals. One of the negative effects of unmanaged changes can be a decrease in quality, an increase in cost and lead time. Changes, if identified on time and properly managed, are the cause of positive effects, including the use of modern science and technology, value engineering, etc. in construction projects. Building Information Modeling System (BIM) having significant advantages in coordinating changes has had a revolutionary development in speeding up changes in architecture, engineering, and construction industry. This research examined the status of the factors related to the contractor in the projects, the requirements and platforms necessary for using BIM in the contracting companies of Shiraz city in order to manage the changes and rework and prevent the time and cost deviations caused by them. Also, by distributing the designed questionnaire among the experts and experts in construction projects and analyzing the data collected by SPSS software, conditions were provided to avoid redundancies and time and cost management of construction projects, with an emphasis on therapeutic projects. . The results showed that the application of the building information knowledge modeling system, according to the existing conditions, has a suitable justification for construction project contracting companies in terms of avoiding rework costs and time delays.

The transportation sector includes activities that are widely effective in the processes of production distribution and consumption of goods and services. so, it plays a fundamental role in the economic growth of countries. However, investment in transportation infrastructure despite the positive effects, may not have maximum effects on growth in developing countries due to mismanagement and lack of proper strategy and plan in infrastructure development. As a result, considering the nature of investment in the transportation sectorm this sector and the growth of the national GDP from different dimensions and angles becomes more important. The current research has investigated this issue based on a "vector error correction model" and its estimation in the period from 1373 to 1399. the relationships of the variables used in this model can be specified in the form of three correlation relationships. These three relationships can be examined under the three relationships explaining real GDP, real exchange rate and real investment in the transportation sector, which respectively describe the behavior of the real sector of the economy, the behavior of the currency market and the behavior of investment in the transportation sector. According to the obtained results, the variable of investment in the transportation sector has an effect on the production variable in the long term, and the extent of this influence is such that each one percent increase in the real investment in the transportation sector can be 0.09 percent in growth Iran's economy will be effective.

Injection soil improvement is one of the methods of modifying the properties of the site of construction projects or existing structures. Several stabilization techniques are available to improve such conditions, including compaction, consolidation, mechanical stabilization, and cement injection into the soil. The injection is often done by filling cavities and fractures with grout or cement mortar. Despite almost the same principles, injection methods have different equipment and procedures. These methods have their characteristics and advantages due to insufficient bearing capacity, shrinkage swelling, settling, and durability. This study intended to review the studies and methods of improving alluvial soils using the cement injection method. After reviewing the results of this study, we can get three main factors: percentage of cement, setting time (sample age), and percentage of coarse soils have a very effective and controlling role in the strength of soil-cement samples, but the effect of these three factors is not the same in increasing strength. The results of such experiments can be used as a basis for quality control of cement injections in porous media, especially in coarse-grained alluvial sediments and jointed and crushed rocks. The resistance of coarse-grained alluvial sediments with the potential for spillage can be increased, during or after tunnel excavation, by adding a minimum percentage of injected cement to the desired strength or design strength, which is essential from the technical and economic justification of injection projects.

Evidence suggests that the role of elites in managing societal affairs is one of the major concerns that needs to be addressed more in developing countries. Increased participation of people, particularly elites, decreases errors in policymaking. Transportation is an essential need in human communities, and economic and social progress are impossible without transportation networks. In this aspect, air transport is the safest and most recent, most modern method of transportation. This study was aimed at identifying factors affecting elite participation in public policies implementation, with an emphasis on air transport. This study identified effective factors in two categories, content and context factors. Semi-structured and in-depth interviews with 15 air transport professionals were conducted using a purposive and snowball approach. Thematic analysis was used to assess the data obtained through interviews. The analysis yielded 190 initial codes, 35 sub-themes, 17 major themes, and 4 organizing themes. The findings were attained through the development of a model that included content drivers, content barriers, context drivers and context barriers to elite participation in public policies implementation. Finally, in addition to discussing research limitations, recommendations for future studies were offered.

The existences of loose soils such as soft sands have always created concerns for bearing the load. Their inability to withstand pressure and weak shear resistance have forced engineers to move the project site or accept expensive methods such as pile driving as solutions to overcome them. Today, many additives such as polymers, lime, cement, etc. have been introduced to improve soil properties and land improvement; however, each of them, having their strengths and weaknesses, has created problems for their use. Cement factory furnace ash, which is one of the by-products in the cement production process; at the outlet, the gases released from the furnace are collected by fabric filters or electrostatic precipitators. Due to its similarity with the compounds found in cement, the compounds of this material have some of the positive properties and characteristics of cement and can be used to stabilize weak soils due to its cheapness. In this research, the effect of cement furnace ash on the engineering properties of unsuitable and weak sand-blasted soil has been investigated, in such a way that cement furnace ash with proportions of 5, 10, 15 and 20% with sand-blasted soil in the periods of 7, 14 and 28 days processing of the combination and direct cutting test have been done on them. Also, in order to create ideal conditions, the standard Proctor compaction test was used to obtain the maximum dry weight of the soil and the optimum humidity for each sample. The results of this research show that the samples with 10% cement furnace ash compared to other samples create a more ideal composition and the shear strength is more than 7 times compared to samples without cement furnace ash.

Choosing the right place is one of the most important decisions to make any plan and project that requires research on the place from different perspectives. Because resource management requires real information, a large amount of detailed information must be collected, combined, and analyzed to nominate different locations, in order to properly assess the factors that may influence the selection. Due to the fact that District 7 is one of the most important population and traffic centers in the metropolis of Tehran and needs more attention from various aspects such as urban studies and urban planning, parking location in this area has been selected as a case study.

In this research, by preparing data and performing location operations for multi-storey car parks, the most suitable uses for creating such spaces are urban uses and the network of roads. Therefore, with the analysis performed in AHP method.

Considering that District 7 is one of the important population and traffic centers of Tehran metropolis and needs more attention from various aspects such as urban studies and urban planning, the results obtained from the weighting of criteria, the most weight to use Bayerand then allocated to the road network. Considering the importance and privilege that Bayer users get in this location, and also considering that the network of passages in locating multi-storey car parks, because it facilitates access conditions, has the highest score after Bayer.

The growth of railway lines has caused engineers to seek to increase the efficiency of the ballasted railway track, and for this reason, they are looking for an increase in the maintenance intervals and a lower life cycle cost. In high-speed railways and lines with high traffic volume, especially railways with stiff and soft subgrade, the issue of line settlement is one of the challenging factors. According to the methods introduced to strengthen the subgrade so far, the use of geogrid is one of the conventional methods to reduce settlement and maintenance operations, which today requires more investigation in its optimal selection. In this article, an attempt has been made to investigate the effectiveness of geogrid to reduce stresses on the subgrade, sub-ballast layer, and ballast layer, and to explain how to choose it based on the technical parameters. In this study, the types of geogrid and the effect of mesh size, applied stress, and its effect on soil resistance have been investigated and the method of achieving the appropriate selection of geogrid has been suggested. Studies show that by using geogrid, the vertical settlement and horizontal movement of the railway panel can be reduced by 70%.

Slopes are one of the main parts of the environment, which are the habitat of many organisms. Annually, some slopes become unstable due to rainfall, in addition to road rainfall, it can decrease or increase the safety factor of the slope. Stabilizing soil slopes against rainfall is one of the basic challenges discussed in the design and implementation of road construction projects. A parametric study has been used to investigate the combined effect of rainfall and road on the stability of soil slopes using SEEP/W and SLOPE/W software. In this study, first, the effect of rainfall with different intensities on the slope without road was performed. According to the results, depending on the location of the road in the slope, the construction of the road can lead to a decrease or an increase in the initial safety factor in the slope. With the increase in intensity and time of rainfall, the seepage front, water pressure and underground water level increase and the safety factor is decreased. By examining the combined effect of rainfall and road in a case study, it was concluded that the construction of the road on the slope will reduce safety factor more severely during rainfall compared to the case without road. Finding of the present study shows the need to consider the combined effect of road and rainfall during slope stability analysis, which can lead to the reduction of landslides adjacent to the roads.

The development of transportation plays an important role in the development of the country's oil industry. Sustainable financing of transportation in this industry will help the sustainable development of the oil industry by considering all dimensions, including economic and environmental. The aim of the current research is to identify and analyze the drivers affecting the future of sustainable financing in the transportation of the oil industry.The present study is post-positivist in terms of philosophical foundations and applied in terms of orientation. To analyze the research data, two quantitative methods of fuzzy Delphi and modified fuzzy Vikor were used. The theoretical population of the research was the managers and senior experts of the oil industry in the field of transportation. Sampling was done judgementally based on the expertise of experts and the sample size was 10 people. Research tools for data collection were interview and questionnaire.After reviewing the literature and interviewing the experts, 29 drivers affecting the future of sustainable financing in the transportation of the oil industry were extracted. Research drivers were screened using fuzzy Delphi. After the fuzzy screening, nine drivers had a defuzzy coefficient higher than 0.7 and were selected for final prioritization with modified fuzzy vikor. Finally, after the final prioritization with the fuzzy Vikor technique, the development drivers of the banking industry had the highest priority. The driver of bunkering industry development had the highest priority. Applied research proposals were developed based on priority drivers. The most important practical suggestions of the research were: The government's investment in providing infrastructure for the bunkering industry, improving the business environment and removing annoying laws to facilitate investment in the country and using the capacity of universities and science and technology parks to strengthen startups and knowledge-based companies.

The implementation of polymer modification on bitumen performance at low temperature is significantly compromised by the breakdown of styrene-butadiene rubber (SBR) polymer during bitumen mixing operations. The effectiveness of using waste edible oil/Sasobit (Sasobit/WCO) as a hot additive mixture has been demonstrated in reducing the adverse effects of thermal aging on bitumen modified with Stysene Butadiene Rubber Bitumen (SB) while maintaining the initial performance of the bitumen. However, few studies have been conducted to further investigate the rheological properties and aging resistance of SB bitumen modified with Sasobit/WCO blends. In this research, three additives - Sasobit, WCO, and Sasobit/WCO composite - were selected on the physical and rheological properties of SB, and they were investigated and also evaluated in those mixtures prepared. In addition, using dynamic shear rheometers (DSR) and bending beam rheometers (BBR), this warm mixture was evaluated on performance grade (PG) and aging resistance SB. According to the results, Sasobit/WCO composites perform better than Sasobit and WCO in reducing the preparation volume. Sasobit/WCO also improves the performance of SB in high and low simultaneously. Compared to hot asphalt mixtures, the addition of Sasobit/WCO reduces the preparation of bitumen mixtures by 19 °C, which contributes to the lowest negative aging temperature on SB performance. In addition, the addition of Sasobit/WCO composite can improve the SB mixture against thermal cracking. After the introduction of Sasobit/WCO, the high PG of SB increased by two grades regardless of whether the effect of warm mixing was taken into account. With the addition of Sasobit/WCO, the acceptability of SB against short-term aging increased.

Recycled asphalt pavement (RAP) has become a common practice in most countries. Hence, the use of rejuvenators along with RAP has become popular with asphalt producers, mainly due to rising raw material costs. In this study, crumb rubber (CR) 2 and waste frying oil (WFO) 3 were used to restore the properties and increase the rutting resistance of RAP. Several physical and rheological properties of bitumen were tested. The results showed that the RAP bitumen samples containing WFO and CR reduce the softening point and increase the degree of penetration. This is related to increasing penetration index. In addition, the viscosity of WFO/CR composite recycled bitumen showed better workability and hardness, as well as low storage stability temperature (less than 2.2 °C) with an acceptable decrease during heating. The rheological properties of WFO/CR with regenerated bitumen were comparable to the control sample. The incorporation of CR with WFO as a hybrid rejuvenator increased the rutting resistance. Therefore, the presence of WFO/CR has a significant effect on the properties of RAP bitumen, while creating a better environment and reducing environmental pollution by reusing waste materials.