###### Abstract
After a few years of passing trucks, loose sleepers and cracks in the track bed slab appeared to varying degrees; Several tunnels on the Yuhuai line have been paved with LSBT, and since the opening of operation, there have been diseases such as sinking of the overall track bed, loose sleepers, and serious slurry eruption, which caused large changes in the geometric dimensions of the line. In addition, these two ballastless track structures are difficult to repair after they are damaged. The LVT is provided with elastic cushions under the concrete supporting blocks and under the rails, and the overall track flexibility is good, which is conducive to reducing the wheel-rail interaction force under heavy-load transportation conditions and improving the stress environment of the track structure. LVT has been successfully applied to the Qinling Tunnel on the Xikang Line in China and the Wushaoling Tunnel on the Lanwu Second Line and other passenger and freight mixed transport lines, and the cumulative laying of more than 300 km has been completed. The Qinling Tunnel and Wushaoling Tunnel have been in operation for nearly 10 years. The LVT structure is in good overall condition in the stable section of the tunnel base. In addition, compared with the double-block type, after the concrete supporting block is damaged and the tunnel base has local diseases, the LVT can be repaired better. In summary, LVT has good overall performance and has a certain scale of engineering application in China. It has accumulated more experience in construction and maintenance and is a relatively mature structure. In addition, relative to the rigid track bed, there is a certain degree of repairaability after the concrete supporting block is damaged and the tunnel is locally damaged. Therefore, the focus is on the selection of LVT structure for heavy-haul railways. The LVT structure (Figure 5) is composed of rails, pre-embedded iron seat fasteners, supporting blocks, rubber boots, lower pads, and track bed slabs, etc. The elasticity of the track structure is provided by rubber boots, under-block rubber pads and fastener systems [9]. Compared with DBT and slab ballastless track, LVT has the advantages of low cost, good elasticity and vibration reduction performance, and convenient maintenance and repair. Compared with other types of ballastless track types, LVT has lower cost and better economy [15]. Therefore, the LVT system has been widely used in domestic and foreign railways and urban rail transit tunnels, such as the English Channel Tunnel, China Yiwan Line, Xiangyu Line, Qiangui Line, Xikang Line, Lanwu Second Line, Hong Kong Metro, Guangzhou Metro, and the United States Atlanta subway and so on. It is highly adaptable to the characteristics of heavy-haul railways, such as high traffic density, short skylight time, large area in the form of tunnels (Figure 6), and widespread distribution in sparsely populated areas. Comprehensive analysis shows that LVT has a good application prospect in the field of heavy-haul railways. In view of the fact that traditional LVT is used in low-axle load railways, and heavy-haul railway trains have heavy axles, it is difficult to meet safety requirements if the traditional structure is still used. Therefore, according to the characteristics of heavy-haul railways, the design optimization and calculation analysis of LVT are carried out to ensure the safety of LVT while ensuring its economic efficiency. The lateral translation and torsional deformation of the rail relative to the sleeper under the action of the wheel-rail force will expand the gauge, change the geometry of the track, and cause track irregularities [16]. With the increase of speed, the increase of wheel-rail effect will aggravate the phenomenon of dynamic gauge expansion [17]. For LVT, under the effect of the lateral load of the train, the elastic support block will create a gap with the track bed, the support block will tilt laterally, the rail will shift and rotate laterally, and the gauge will expand, causing the rail to overturn [18; 19; 20].