Several questions about high speed rail and subgrade.
Not only high-speed rail, but also the current speed rail, almost all have adopted a seamless line, since you need to know more about the relevant content
You said in front of the concrete board has already said is the track board, the following "cushion" should refer to the CA mortar filling layer, that is, cement, asphalt, mortar layer. The main function is to support the track plate, to buffer the load and shock absorption of the high speed train. The main materials are: cement, emulsified asphalt, fine aggregate, water and a variety of additives. The edge breakage has no direct effect on its performance, but in the long run there must be some adverse effects, especially the ageing resistance.
You said concrete thick plate, should be the track board, that is, the use of ballastless track line, there is gravel laying corresponding to the ballasted track. This has nothing to do with operational safety. Many high-speed rail lines are adopted both at home and abroad, and ballasted tracks are adopted.
