###### Abstract
The longitudinal and transverse structural behavior of QHTs on bridges were examined through an experiment program using actual-size QHT specimens; subsequently, the minimum required frictional coefficient was deduced [22; 23]. There are two methods for deducing track-bridge interactions. First, a separate analysis method simply sums the stress and deformation generated by the temperature and train load, respectively. Second, a sequential analysis method solves the stress and deformation in a sequential manner in the order of temperature and train-load generation. Sequential analysis faithfully examines the behavior of the track and the bridge; however, its implementation is rather complicated. It is known that separate analysis conservatively evaluates rail stress compared to sequential analysis, whereas it is the other way around with regard to displacement [24]. A separate analysis is commonly conducted in field projects, as investigated in previous studies [19; 20; 21; 22; 23]. For implementing sequential analysis, the structural properties of the longitudinal resistance of the track should consider the existence of train load after temperature changes [25; 26]. As the longitudinal resistance normally comes from a rail fastener in a typical slab track, the typical sequential analysis considers nonlinear behavior between the rail and track without the frictional behavior between the track and the bridge. QHT track segments and the bridge are structurally connected by anchor blocks that comprise a steel bracket, laterally welded stud shear connectors, and post-installed anchors. Figure 1 shows the construction order of QHTs on railway bridges [22]. After removing all ballasts on the existing ballast track, anchor brackets are positioned at the center of each segment of the QHT (Figure 1a). The washed ballasts are laid on a cast form using geotextiles on top of the bridge deck (Figure 1b). The track skeletons, to which concrete sleepers and rails are connected, are installed on the laid ballast (Figure 1c). Once the laid ballast stabilizes after a few days, quick-hardening mortar is injected and cured (Figure 1d). When the quick-hardening mortar exhibits sufficient strength, the post-installed anchors are installed on the bridge deck (Figure 1e). After the post-installed anchors are installed, the shear resistance of the anchor blocks can withstand temperature and train loads. If a longitudinal load is delivered to the anchor blocks before the injected quick-hardening mortar gains sufficient strength and hardens, cracks may occur in the quick-hardened concrete where the shear connectors are embedded. Thus, the post-installed anchors must be installed after the mortar develops sufficient strength. The compressive strength of quick-hardening mortar is 9.6 MPa two hours after curing, and 30 MPa after one day of curing [27]. Therefore, the post-installed anchors can be installed when the QHT is at least one day old. Before installing post-installed anchors, the longitudinal resistance only comes from the frictional forces between the underside of the QHT and the top of the bridge deck. In this study, the track-bridge interaction is examined when only frictional resistance exists before the post-installed anchors are installed. Here, examining the longitudinal relative displacement of QHT segments, as well as rail stresses due to the interaction, are important. A sequential analysis was performed herein because a separate analysis may underestimate the displacement. The friction between track and bridge and the structural behavior of an anchor were evaluated based on the experimental results of a previous study [22], and the effects caused by a change in friction coefficient were also examined.