## 1 Introduction  
Modern tram belongs to the category of urban rail transit, which is similar to subways and light rail transit, but at the same time has its own unique technical and operational characteristics. Modern tram has undergone a comprehensive transformation and upgrade using components of traditional tram, establishing these tram as a new type of public transportation [1; 2; 3; 4], as shown in Figure 1. Modern tram can solve the disadvantages of the existing subways, such as expensive investments and long construction stage [5; 6]. Based on the old tram system, the modern tram system has been upgraded and modified to reduce noise. The characteristics of low vibration, green environmental protection, low investment, and quick returns comprise the new direction of urban rail transit to the suburbs [7; 8; 9]. In view of the complex forms of the ballastless tracks for tram, the weak subgrade, and the unique vehicle type, it is necessary to redesign the under-track infrastructure that is compatible with these ballastless tracks [10; 11; 12]. During the construction of the existing embedded track structure, it is difficult to adjust the pouring self-compacting concrete, the geometry of the track structure is not easy to adjust, and the track slab hosting work is relatively heavy, requiring the cooperation of large construction machinery, especially in urban road sections, which will affect the construction progress [13] (Figure 2). Therefore, we have designed a novel fastener type ballastless track (NFTBT) for tram [14], which eliminates the need for spaced cable passage sections, and facilitates the passage and fixation of cables in the tram's operation section. The NFTBT's geometric shape is easily adjusted, which can accelerate the construction progress, as shown in Figure 3. The NFTBT's structure includes a prefabricated track slab body, on which is set a rail seat for fixing groove-shaped rails. The rails are fixed to the rail seat through fasteners to enable the tracks' adjustment and to affix the geometry of the track, which is set at the centerline of the track slab. There are grouting holes and a cable duct laterally penetrating the main body of the prefabricated track slab is provided. Figure 1: Modern tram. Figure 3: Schematic diagram of NFTBT’s structure: (**a**) the whole frame; (**b**) schematic diagram of the main view; (**c**) schematic diagram of the side view. Figure 2: Tram track construction site. Compared with other types of tram's track structures, the NFTBT has the following advantages:  
(1) In the NFTBT's structure, a large area of grouting holes is set at the longitudinal centerline of the track slab. This is conducive to pouring the self-compacting concrete adjustment layer, it facilitates vibrating and compaction, reduces the difficulty of adjusting the geometry of the track structure, and can accelerate the construction progress. (2) In the NFTBT's structure, a pre-embedded cable channel penetrating the cross-section of the track is set at the center of the track slab, which is beneficial for the cables of the tram's operation section to pass through the line laterally, and there is no need to install cable passage sections at intervals. (3) The NFTBT can be prefabricated in the factory, which reduces the workload and person-hours of on-site concrete pouring and realizes the goal of environmentally friendly construction. To study the mechanical properties of the NFTBT's structure during the construction and tram operation stages, it is necessary to select an appropriate mechanical analysis method for research. Since the track structure directly affects the operational safety and stability of modern tram systems [15,16], there is still a lack of research in the existing literature. [PERSON] et al. [17,18] conducted a mechanical analysis on the ladder track structure of the Dalian tram system and put forward optimization suggestions. [PERSON] [19] simulated the wheel-rail dynamic response when a tram passes through a curve. [PERSON] et al.