# Load Transfer Efficiency Based on Structural Deflection Assessment of the Precast Floating Track
## 3 Experimental Program  
To evaluate the structural safety of the prefabricated floating track, we tested the bending performance of the slab panel in conjunction with a designed trainload. The performance of the vibration control system was compared with the stability of the track system and its ability to resist train loads. The detailed specifications of the slab panel are shown in Table 1. The test was conducted using the same structural assembly specimens, to evaluate the behavior of track systems, which consisted of rails, slab panels, and vibration isolators composed of precast panels. The test was carried out by applying loads on the three-panel test, two load cases were conducted: loaded on the 2 nd panel at the 2/4 point, and on the 2 nd panel at 4/4 point. Table 2 shows the specifications of the load test. In load case I, the maximum bending capacity of the structure was verified through the deflection of rail and panel. 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. The load force rate (DIN45673-1) was set to 2 kN/s, then remain the maximum load time was 10 s, and the displacement of the rail and panel were measure while removing the load at the same speed again. The loading test assemblies for the three-panel slab are shown in Figures 6 and 7. First, the anti-vibration devices were installed at the bottom of the panels. Next, the panels were fixed on the flat floor by screws, and finally, the load was applied at two load cases as mention above. The linear voltage differential transducers (LVDT) were set to 50 mm mounted on the rails; panels are shown in Figure 7 to measure the behavior of structures. The load capacity was set to 500 kN using a dynamic actuator, and the data was collected using a TDS-601 data logger, which was manufactured by Tokyo Corp.  
Figure 4: Fabrication process of precast floating panel: (**a**) assembly of rebar, (**b**) concrete pouring, (**c**) curing, and (**d**) prototype of precast floating panels.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Specifications** & \multicolumn{2}{c}{**Dimensions**} \\ \hline Size of Panel (m) & 4.925 (L) \(\times\) 2.4 (W) \(\times\) 0.3 (H) \\ Concrete Strength (MPa) & 45 \\ Weight of Panel (ton) & 7.6 \\ Vertical Support Stiffness of Anti-vibration Device (kN/mm) & 22.5 \\ Lateral Support Stiffness of Anti-vibration Device (kN/mm) & 18 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Specification of Specim.  
Figure 5: Assembly test specifications: (**a**) full scale static loading diagram and (**b**) installation of assembly test.  
Figure 6: Structural assembly of three slab panel with 60 K rail: (**a**) Load case I: center loading point, and (**b**) Load case II: 2 nd panel at 4/4 loading point test.