Developing a New Vibration Analysis Calculative Method for Esfahan Subway Train and Railways Design, Manufacturing and Construction
The simulated mass and spring evaluation for subway or railways construction and installation have wide applications in rail industries. This kind of design should be optimize all related parameters to reduce the amount of vibration in cities, residential areas, historical zones and other critical locations. Finite element method used too much to analyze such applications with an excellent accuracy but developing some simple, fast and user friendly evaluation always was required in subway industry. In addition, process parameter optimization required in railways to achieve optimal railways design with maximum safety, reliability and performance. The simple but useful simulated mass and spring evaluation system developed for Esfahan subway construction. This method discussed in this paper. Esfahan subway construction has a historical zone. Historical buildings should protect from harmful vibrations. Polyurethane layer used to reduce vibrations. This layer completely covered by concrete layers in all directions. It is worthy to know that, all the operation criteria like displacement and stress could be adapted with all vibration criteria like natural frequency, operation frequency and damping. Adaptation performed by changing in polyurethane layer thickness. The results showed that if 25-millimeter thickness polyurethane layer covered completely by two concrete layers with 12 millimeter thickness, the amounts of vibrations reduce considerably. In addition, it strongly recommended increasing the polyurethane layer up to 37 millimeter in historical zone to prevent potential harmful effects. The results confirmed by other commercial methods. The calculative method successfully performed. Furthermore, it is important to reduce maintenance costs in any potential design. The process parameter like rail ways dimension, rail ways material, cabins loading, cabins quality, cabins dimension and polyurethane layer thickness properly designed to keep the subway natural frequency around 18 Hz ( less than allowable 20 Hz). Numerical design results will protect all historical buildings, palaces paintings and old bridges in future subway operation times. In addition, some interesting patent and innovation in rail industry like Suspension mass tuned vibration reducer, short sleeper vibration-attenuation fastener and airtight track vibration noise reducing fastener discussed in this paper.
Landslide Mitigation and its Risk Controlling
In this paper, different types of landslides controlling methods and the importance of their controlling in a multipurpose project is investigated. Site mobilization duty includes managing the facilities placement to keep risks down using the best arrangement of facilities. This duty can be assisted by computer programs. A landslide is a geological phenomenon which includes a wide range of ground movement. Landslide is one the most important problems that can harm site mobilization. That's why it should be identified in a large project such as dam construction. Thus, in this paper site mobilization and its landslide risk controlling is presented. Also, different landslide controlling methods are presented.
Modelling and experiment of railway ballast vibrations
The vibration of railway ballast is a key factor to cause track geometry change and increase of track maintenance costs. So far the methods for analyzing and testing the vibration of the granular ballast have not been well formed. In this paper, a five-parameter model for analysis of the ballast vibration is established based upon the hypothesis that the load-transmission from a sleeper to the ballast approximately coincides with the cone distribution. The concepts of shear stiffness and shear damping of the ballast are introduced in the model in order to consider the continuity of the interlocking ballast granules. A full-scale field experiment is carried out to measure the ballast acceleration excited by moving trains. Theoretical simulation results agree well with the measured results. Hence the proposed ballast vibration model has been validated.