• Structural Engineering and Mechanics
• /
• v.26 no.2
• /
• pp.111-126
• /
• 2007

Dynamic responses of the bridge for a straddle-type monorail subjected to the ground motion of high probability to occur are investigated by means of a three-dimensional traffic-induced vibration analysis to clarify the effect of a train's dynamic system on seismic responses of a monorail bridge. A 15DOFs model is assumed for a car in the monorail train. The validity of developed equations of motion for a monorail train-bridge interaction system is verified by comparison with the field-test data. The inertia effect due to a ground motion is combined with the monorail train-bridge interaction system to investigate the seismic response of the monorail bridge under a moving train. An interesting result is that the dynamic system of the train on monorail bridges can act as a damper during earthquakes. The observation of numerical results also points out that the damper effect due to the dynamic system of the monorail train tends to decrease with increasing speed of the train.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1293-1299
• /
• 2010

Daegu urban railroad line 3 is introduced with straddle-type monorail system within the country at the first time. This system is long line with 24km in total length which has not the results of construction in Korea. The rail beam of monorail bridge to be constructed/ installed in the city is adopted on the basis of the PSC rail beam. It is required to apply the steel rail beam at rapid/ curved line parts or location to be required the long span bridge as passing river and intersection. The composition of span bridge is various and the height of bridge is change with each section and exist the different curve radius due to all section is passes in the city. The rail beam shall be considered the ground conditions and then consider the construction methods. It is analyzed to construction period of PSC rail beam to be linked with period of infrastructure construction and construction of steel rail beam, structure construction of station etc. It is compared to crane construction methods and launching girder as alternative construction methods and propose to upper construction methods which is superior in economic and construction.

• Steel and Composite Structures
• /
• v.27 no.2
• /
• pp.161-175
• /
• 2018

In this study, in-situ dynamic tests of the world's longest steel box tied-arch bridge over the Yangtze River, China, are reported. The double deck bridge supports highway and monorail systems at upper and lower levels, respectively. Strain, displacement, and acceleration responses were measured and used to investigate the vibration characteristics of the bridge when excited by running trains and/or trucks at a speed of 5-60 km/h, train braking, and truck bouncing. Impact factors were correlated with the running speed of trains and trucks. A three-dimensional finite element model of the coupled monorail-train-bridge vibration system accounting for track irregularities was established to understand the system behavior and validated by the experimental results. Truck bouncing was the dominant impact factor on bridge responses. The running speed of vehicles determined the riding comfort of traveling trains.