جستجوی مقالات مرتبط با کلیدواژه « subway » در نشریات گروه « عمران »

Noise pollution in urban transportation systems is one of the hazards that can always endanger the health of passengers and affect their use of public transportation.

Noise pollution was assessed on station platforms, passenger cars as well as train wagons. According to the sound level data of the stations and the collected data, the modeling was done using a regression linear model. Using correlation analysis, the effect of various factors on noise pollution index was investigated.

The equivalent noise level index in a certain period of time Leq in Nawab station is more than the other 3 stations that the initial assumption about the noise pollution rate is higher due to the large number of passengers. Also Sanat Square was the quietest station among the studied stations. The equivalent sound level was picked up at a certain point in Leq at Nawab Station 83 and Sanat Square 77, which is another initial assumption about the recorded environmental pollution and lack of close monitoring.

The permissible noise pollution limit (65 decibels) has been higher in most of the measured points, so that in Maidan Sanat station, which was the quietest station at the time of train arrival and departure, the equivalent sound level of 77 decibels was collected. Has been above the standard.

The use of tunnels, tunnels, and mines by humans dates back hundreds or even thousands of years. The construction of communication tunnels and water transfer in mountainous areas to overcome the steep topography has been increasing in recent centuries. In the new era, due to the expansion of cities and the density of population centers in the world and the prediction of much higher density of Yazr cities in the future, the need to use the third dimension of land, namely increasing the height of buildings and construction of multi-storey highways on the ground. Also, the creation of service roads and spaces such as subways and underground urban communication tunnels is felt in a tangible way. In Iran, the idea of ​​using intercity tunnels has been implemented since the beginning of this solar century. . But the study plan and the first phase of Tehran metro design was done in the early 50's by the French company "Sofroto". There are various methods in the implementation of guard structures for drilling tunnels, underground stations, mines and in general "underground structures" that the use of metal frames of the Austrian NATM in the construction of Tehran meters became common. But during 1984 and 1985, for the first time, concrete arches or ribs were used to reinforce the soil of the drilling site, which is known as the "Russian" method, and for the first time in the area of ​​Shemiran Gate Station by Dr. Sedghiani, Professor of Geotechnics, University of Tehran. Designed and executed by Kova Construction Company. This article is the result of the author's ten years of experience in various subway projects in Tehran and Karaj.

In this article with simulation of Tehran subway second type rolling stock, dynamic performance of this train has been studied. Dynamic simulation of Tehran subway has been simulated in UM (universal mechanism) package. At first train bogie parts has been drawn in 3D software package Solid works and moment of inertia and mass of each part has been extracted. In Solid works software the bogie part has been attached and complete model of bogie imported to Dynamic simulation software. In Dynamic simulation of Tehran subway rolling stock, primary and secondary suspensions were differ from conventional bogies that has been used in Iranian railway and simulation should be done exactly. After this work dynamic simulation has been done for hunting speed of wagon and acceleration of wagon body has been obtained in vertical and lateral directions. with the result that has been extracted from dynamic performance of train, the effect of hunting speed on lateral wheelset lateral displacement and angle of attack in left wheel of first wheelset has been comprised .ride index criteria for calculation of Tehran subway has been explained .for simulation of train, track irregularity inputted in UM software for ride index has been calculated in lateral and vertical directions. According to secondary suspension of Tehran subway train body acceleration and ride comfort of this train simulated. According to ride comfort result of this train , the result of Tehran subway rolling stock has been compared with standard value .

This study aimed at investigating air travellers’ behaviour with regard to choices for ground access to Imam Khomeini International Airport. The choices included subway, bus, carpooling, taxi, private car (parking) and private car (car drop-off). Data collection for this study was done during three days in summer, 2014, and Multinomial logit modelling was employed for this purpose. The survey was administered as a face to face interview in Imam Khomeini International Airport, which is located in Tehran, Iran. A total number of 257 questionnaires were collected, with the degree of validation being 34%. The most important results of this research indicate that the majority of imam Khomeini passengers have a high income(%90of them have 1.5 million tomans per month or higher) and car ownership(%92 of them have at least one car in their household). Considering that these passengers don’t have intention for using metro, with increasing the travel time, public transportation costs (e.g. parking cost) and improving metro service qulity (e.g. increasing the reliability and decreasing the travel time) , it may be possible to absorb them to use metro.

The most important indicator of a project’s success is not only it should be cost-effective, but also it should be ended on the predicted time. In some projects like constructing subways, dams and so on, delay in construction causes big problems in financial, social or political levels in the countries. To reduce or eliminate delays in construction projects, time optimization should be planned. The main goal of this project is to study the time delay in construction of Karaj subway. In this regard the reasons are recognized and evaluated. In the first step, by reviewing project documents and designing a questionnaire which was completed by a set of experts, factors of delay in constructing Karaj subway were recognized. In the next step, by using multi-criteria decision-making methods, these factors were phased out, weighted and prioritized. At the end, by using Fuzzy logic and to estimate the delay of projects, a method was provided that according to it the project manager can use experts’ ideas and recognizes how much this project has progress and do necessary actions to have a more rapid exploitation.

Urban infrastructure projects are considered the heart of the economy of countries and productivity of these projects is fundamental in development strategy of countries. One of the important determining factors in the success of major projects, especially subway lines construction projects is the managers’ performance in interacting with involving project factors and considering their expectations and demands. In this study, first by offering a theoretical framework, the required processes to model the expectations of key stakeholders is expressed and according to the proposed pattern, project stakeholders are identified initially and by identifying the stakeholder expectations and determining the key stakeholders, the research enters the model designing phase. In the final stage which is modeling the expectations of key stakeholders, the expectations’ model will be designed using the pattern extracted from the QFD approach. The stakeholders’ expectations model shows the expectations of different stakeholder groups from the project. For designing this model, Mashhad Urban Railways (MUR) construction project is studied. The results showed that the definitive stakeholders have the highest expectations level. “Paying attention to the quality standards of project’s implementation methods” and “paying attention to the project’s reporting system” are the most significant expectations; since all the key stakeholders have such expectations. Results also showed that the three types of stakeholders consisting of “dormant, discretionary and demanding” are not among key stakeholders; therefore, in the expectations model of key stakeholders, they don’t have any expectations.

Summary The purpose of this research is to obtain the requirements of non-operational defenses in the design of metro station. This paper presents some criteria to reduce damages resulting from the enemy threats by using passive defense.
Introduction Subways as one of the critical and practical infrastructures with dual functions can be considered as a settlement for people during crisis and threat. The principles of safety and protection against natural and unnatural threats should be carefully regarded in the design of subways. Thus, to provide safety and protection against threats, the passive defense requirements in subways should be considered.
Methodology and Approaches The research methodology is of descriptive-analytical type and the technique used in this research is Delphi. The statistical population of the research is all the experts in the field of passive defense and architecture, and 12 individuals, for instance, have been selected from these experts. The average of the views of the members of the Working Group 4 indicates a high agreement among them.
Results and Conclusions The results of this research show that among the proposed architectural requirements of passive defense, the subway station is used as a refuge in the time of crisis with an average of 4.91 and has the highest score. The use of suitable bends with respect to engineering principles (90 degrees bends) with score or importance of 4.84 is the second requirement among the passive defense requirements. The maximum accessible radius to the station entrance is 500 meters. The third priority is the architectural requirements of the defense, and the provision of space and space to meet the essential needs and services of the people is the fourth priority. The necessity of self-sufficiency of ventilation systems, the existence of multiple ventilation ducts to deal with airborne bombs, emergency exits with the depth greater than the depth of the asylum seeker's location, adequate width and safety of tunnels for passage of persons, are the next priorities of these requirements. Finally, the necessary electrical systems and lighting of tunnels, the use of security and security systems, and the existence of an independent and emergency communication network for communication with the environment with score averages of 4.28, 4.18 and 4.11, respectively, are the last priorities of these requirement

Excavation tunnels subway traditional and mechanized two methods of all sections are done.Method selection the tunnel to the tunnel, project scheduling, overburden status, urban location and traffic, geological conditions, ground level subsidence, and other considerations, the efficiency of the method is dependent.This paper introduces a a variety of tunnel excavation methods and the advantages and disadvantages of their perform operations and processes are briefly described.The purpose of this paper is to provide young engineers familiar with the basic concepts are the tunneling industry.

After dig projects off the underground and install a temporary consolidate¡ change behavior and movement of the earth and the steady state will be until the sustainability Movements are altered and these changes also can have an impact the structural behavior of the tunnel. For record and analyze the behavior must inside the tunnel instrumentation and data analysis instrumentation can specify the amount and type of movement occurred. In the present paper¡ the case study projects carried out line a subway Qom has been one of the non-mechanized excavation of tunnels with the length of 700 meters of we have. In this study¡ 3 section
100-meter tunnels to the first tunnel¡ 100 intermediate and 100-meter tunnel¡ the tunnel endpoints analyzed and the most stressful parts of the movements have been characterized and reviews that the tunnel will show what passage of time first¡ middle and toward the end of the tunnel¡ what are the behaviors. Results obtained the fact that most of the tunnel and change behavior in first 100 meters of tunnel openings consolidate their show and the implementation will be very careful.

Due to the growth of urbanization, public transportation has been seriously considered in many mega cities in recent years and therefore utilization of all modes of public transportation by prioritizing them is one of the most significant issues in such cities. The purpose of this paper is to provide a method for prioritizing the public transportation in City of Tehran by applying an Analytic Hierarchy Process (AHP). In this research, at the first step, the effective criteria in priority of public transportation were defined, then by applying an expert choice technique and completing. questioners by experts in Transportation and Traffic Department of Tehran Municipality, the criteria were `revised and finalized. To complete the research, a Group Hierarchal Analysis Method was used to prioritize the existing public transportation modes in City of Tehran. The results were then compared to budget allocated to each mode of public transportation in Tehran in the past ten years, and recommendations were suggested to correct the Budget Allocation System. Results show that the subway has the highest priority, followed by BRT, bus, van taxi and taxi. Also the sensitivity analysis showed that the ranking results have the highest sensitivity to the “aim of travel” and can highly be affected by this criterion. Based on results of this research, subway, as a mode of transportation has the highest priority in the City of Tehran and therefore the allocation of public budget should be revised according to this priority.