PURPOSES : The objective of this study is to develop an optimal placement of the overturning prevention device based on a 3D object model during the development of the girder-type overturning prevention device for the remote control construction of bridges METHODS : Based on existing construction methods and literature research, a detailed design model of a phase-optimized conduction prevention device is presented. The 3D-object model data, optimal placement, and an operating range of the equipment developed for the remote control construction of bridge girders were considered. RESULTS : The shape of the overturning prevention device was selected taking into account the dimensions and operating range of numerous devices developed for the remote control construction of the bridge. In particular, the detachable device was chosen to allow a trouble-free construction considering the spacing between the pier cap of the bridge and the girders. The overturning prevention device presented based on this 3D object model will be manufactured as a mock-up and used for a demonstration project on remote control bridge construction. CONCLUSIONS : This will enable easy and economical construction as this development will support remote control construction of bridge girders to avoid accidents such as workers falling from high places like piers.

PURPOSES : The percentage of vehicle overturning accidents is 16.3% of vehicle alone fatal accidents, with a fatality rate of 9.0%, accounting for a high proportion, and heavy vehicles with a high center of gravity are vulnerable to overturning accidents. In the standard guidelines of Super-Bus Rapid Transit(S-BRT), it is recommended to install physical facilities that separate buses from other traffic on dedicated bus ways, and lane separation facilities are being developed. To develop low-profile lane separation facilities that do not interfere with sight obstruction for pedestrians and drivers, it is necessary to review the height of lane separation facilities to prevent overturning crashes of heavy vehicles. METHODS : Heavy vehicle impact conditions of 8ton-55km/h-15°, 8ton-55km/h-20°, 8ton-65km/h-15°, and 8ton-65km/h-20°were applied to compare the vehicle behavior by the height of lane separation facilities using LS-DYNA, a three-dimensional nonlinear impact analysis program based on speed and angle changes. In addition, the behavior of the vehicle after the collision was analyzed to examine the impact conditions in which an overturning crash occurs when a heavy vehicle collides with a low-profile lane separation facility and the appropriate height of the facility to prevent overturning. RESULTS : In general, under the 8ton-65km/h-15°condition, which is a heavy vehicle impact condition used in the performance standard of the barrier, the vehicle’s behavior after the collision was stable as the height of the lane separation facility increased. CONCLUSIONS : Therefore, when the impact conditions were 8ton-65km/h-15°or less, it was determined that the appropriate height to prevent the condition of the lane separation facility was 400mm or more.

In this study, an analysis model with circular arc on the plane is chosen as a representative section of the steel box girder. The steel box girder has thin-walled cross section. When working load is increased in the outer sector, the behavior of the negative reaction and overturning moment are shown up. Curved bridge has a central angle from about 4 to 26 degree. Negative reaction and overturning moment are analyzed according to increase of a central angle from 4 to 26 degree as well as shape factor.

Compare to the straight girders, horizontally girders show complex behavior because torsional moments are always acting on the structure. Because of the torsional moments, there can be negative reaction forces at some supports, and that can cause the overturning of super-structure. Sometimes, this stability problem is more important in the construction stage rather than after construction. However, it is rarely considered in design except special case. In this paper, numerical analysis is performed to investigate the reaction forces characteristic of horizontally curved steel box girder.