Study on Structural Performance of Precast Track of Discrete Panel Supporting Type for Rapid Ballast Improvement

Abstract

The conventional ballast track needs to be improved and replaced due to the rapid degradation of the track. While operating the conventional line, the track structure needs to be rapidly improved and constructed in a narrow restricted tunnel space during railway blockade time. Therefore, the precast slab track of discrete panel supporting rapid construction was developed, and analysis and performance tests were conducted. In this study, vehicle track interaction analysis was performed to evaluate the behavior that may occur in the transition of the ballast track and the slab track in the field and to evaluate the safety of the structure during the train operation. In addition, to verify the performance of the prefabricated slab under the load of the train and its applicability to the actual operating line, a load test was performed on the assembly test body consisting of precast panels, rails, and panel-discretely supporting elastic rubber. The results of the test indicated that the rails and panels of the assembled test body satisfied the required performance test and secured structural safety.

Assessment of Structural Dynamic Response and Vehicle-Track Interaction of Precast Slab Track Systems

“…In this paper, the KR-60 rail was mounted on both types of precast slab tracks. The allowable stress of the KR-60 rail is normally 130 MPa [5]. The reference value to analyze the rail stresses is 70% [27] of 130 MPa and equal to 90 MPa.…”

“…Nowadays, with the development of technology, concrete slab track systems are an alternative method that can solve these problems of the ballasted track with their excellent durability under the trainloads created by the high speed or the increasing of the axle load [4]. Although the initial construction cost of concrete track structure is 1.3-1.5 times higher than ballasted track, the Life Cycle Cost evaluation pointed out that it is possible in the long term this cost can be recovered after 11-12 years of operation based on the maintenance costs [5].…”

Load Transfer Efficiency Based on Structural Deflection Assessment of the Precast Floating Track

“…Meanwhile, the purpose of load case II was to determine the load transfer efficiency between the panels. According to the Korea construction rules for the railroad (Rule number 16), in the tunnel section, the standard live load EL-18 was used to apply for the designed load (180 kN) and in preparation for installing this type of track in conventional line [20] , more than 250 kN of axle load must be reviewed so that the test was performed through the load up to 440 kN which is calculated based on the static axle load of Korean standard (KRL-2012) for conventional passenger and freight train (220 kN) and the dynamic amplification factor (2.00) according to Eisenmann formula [1]. In Figure 5 a full-scale load test was conducted using monotonic loads of 150, 200, 250, 300, 350, 380, 410, and 440 kN.…”