In the construction of high-speed railway, it is necessary to ensure the durability and reliability of the foundation under the rail. This requires that special technical measures must be taken to ensure the selection of lines, the crossing of rivers and roads, deformation control and so on.
Technical type
National high-speed railways (high-speed railways), national heavy-haul railways, national I-III railways (national railways I-III) and urban (rail transit) I-V railways. Among them, high-speed railway and heavy-haul railway are special types of passenger dedicated line and freight dedicated line respectively. The primary and secondary railways of urban rail transit belong to the subway system, and the rest are light rail systems. PS: Different countries or regions have different technical grading standards for their own railways in different periods.
The technical level reflects the construction difficulty and transportation capacity of a certain section of railway, which is closely related to passenger flow or cargo flow. Usually, a certain passenger and freight volume is taken as an important measure, and other corresponding design requirements are attached. Generally speaking, the higher the technical level of the railway, the higher the level of other aspects (such as speed level and administrative level), but there is no absolute relationship. For example, the Qinghai-Tibet Railway is the national railway I, but the speed level is very low, about120km/h; Nanning-guangzhou railway is also a first-class national railway, but the speed level is very high, 250 km/h.