STUDY ON DYNAMIC BEHAVIOR ANALYSIS OF HIGH SPEED RAILWAY BRIDGE TYPE OF SIMPLY SUPPORTED BEAM SUBJECTED TRAIN LOAD

• Main Author: Noviansyah, Rizki
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68982
• Institution: Institut Teknologi Bandung

The high-speed rail bridge is different from the train bridge in general, because the train that passes through the bridge will operate at a high speed of 350 km/h. High train speed will cause a high dynamic effect on the bridge so that this dynamic effect is often a determining factor in the design. The dynamic effects that occur can be in the form of acceleration and resonance on the bridge. High acceleration on the bridge will cause driving discomfort for passengers and instability on the train track. While the resonance on the bridge will cause an increase in the acceleration of the bridge significantly. The purpose of this research is to conduct a parametric study to determine the most influential parameters in the dynamic behavior of the bridge that is passed by the train load which will be evaluated with Eurocode and Chinacode. The linear time history analysis due to the high speed train load was carried out on a box girder bridge structure of the simply supported beam type with span variations of 24m, 32m, 40m, and 48m represented by a natural frequency structure. The bridge is loaded with dynamic Eurocode High Speed Load Model (HSLM) trains A1 to A10 and actual trains CR400AF with speed variations of 100 to 450 km/h. The results of the analysis show that the speed of the train, the position of the train, the configuration of the axle distance of the train, the load of the train, and the frequency of the bridge have a great influence on the dynamic response of the bridge. The speed of the train can affect the frequency of the load which has an impact on increasing the dynamic response value of the bridge until resonance occurs. The position of the train that provides maximum response is the position where two trains enter the bridge simultaneously. The configuration of the distance between the train axles with L/D ratio > 1.5 affects the peak resonance position at high speed and L/D < 1.5 affects the resonance peak at low speed. Variations in the span of the bridge affect the natural frequency of the structure where a high structure frequency gives a resonant peak at high speeds and a low structure frequency gives a resonance peak at low speeds. Dynamic Amplification Factor (DAF) is influenced by train speed, bridge frequency, and train axle distance configuration. This can have an effect on the position of the peak of the resonance occurring within the design speed range or outside. If the resonance peak is outside the design speed range, it is sufficient to carry out a static analysis of the bridge with DAF, and if the resonance peak is in the design speed range, dynamic analysis is required to ensure the safety and comfort of the bridge. The Eurocode and Chinacode have taken into account the effects of speed, bridge frequency, and train axle distance configurations so that the code provides conservative results in a DAF-based analysis.