سيددانيال موسوي

In order to improve the quality of railway service, it is necessary to provide conditions for increasing train speeds in a way that the time for passenger and freight transportation is as low as possible based on the infrastructure conditions in the country. This will be possible by improving the performance of various railway structures involved in this issue, such as the railway vehicle, line and track structures (including railway bridges). In this regard, to examine and analyze the bridge with concrete slab deck as the most frequent type of bridge in the rail network against increasing train speeds, as mentioned in the first chapter of the thesis and in the research objectives section, four span lengths have been considered for analysis. Based on the assumptions mentioned in the first chapter and the validation results mentioned in the second chapter, these bridges have been modeled as three-dimensional finite elements and analyzed. In order to examine how to improve the performance levels of the bridge and the passing train against increasing train speeds, changing the bridge bearing conditions has been eva‎luated as a solution. For this purpose, elastic cushions (neoprene) in accordance with the technical specifications have been used. Another objective of this thesis was to investigate the effect of two solutions for reducing the stiffness of pavement components on the responses of bridge decks in order to increase train speed. To reduce the stiffness of the ballasted bridge pavement components, the first change was to reduce the stiffness of the fastening system in the bridge pavement, and the second change was to use a resilient layer of crumb rubber as the sub-ballast layer. The results showed that reducing the stiffness of the bearing increased the acceleration of the bridge deck and increased passenger travel comfort, and vice versa. The results also showed that reducing the stiffness of the pavement layer with the two aforementioned solutions improved the performance of bridges and passenger travel comfort.

پل با عرشه دال بتني , افزايش سرعت قطار , سختي قائم خط , لايه ارتجاعي , مدل المان محدود

Concrete slab deck bridge , Increasing train speed , Track vertical stiffness , Elastic layer , Finite element model

Seyed Danial Mousavi

Javad Sadeghi and Jabbar Ali Zakeri