How to solve the problem of thermal expansion and cold contraction of high-speed rail?

The method to solve the problem of rail thermal expansion and cold contraction in railway lines is generally to use fasteners, that is, to replace spring fasteners with spring fasteners (also known as elastic fasteners) and fix the rail tightly on the sleeper, so as to forcibly digest the energy generated by thermal expansion and cold contraction. However, there is a problem in this way, that is, when the energy generated by thermal expansion and contraction in unit distance is greater than the adhesion of sleeper, the rail will be raised and the rail of sleeper will be twisted in unit distance. In order to solve this problem, the railway department drilled several holes in the rail waist within a certain distance to release the energy generated by thermal expansion and cold contraction, and reserved rail joints within a certain distance (about 1500m) to assist in releasing the energy generated by thermal expansion and cold contraction, thus solving the problem of rail thermal expansion and cold contraction. First of all, the first point is that the steel of the rail is not made in China, but all imported, so as to ensure the quality of the rail to the greatest extent. The second point is to use new fasteners to fix the rail on the ballast bed more firmly. The high-speed railway basically adopts ballastless technology, which is better than the ordinary railway. Third, when laying rails in construction, try to choose the time when the season or time period has the least influence on the thermal expansion and cold contraction of rails, so that the problems caused by laying will be smaller. The Beijing-Tianjin high-speed railway under construction is a super-long seamless rail, which will only have joints in the turnout area of the station. Taking the unit rail between two stations as an observation unit, observation piles are buried in the shoulders on both sides of each unit rail, and the creep of the unit rail is measured regularly. When the creep amount is abnormal (that is, the internal stress is abnormal), it is necessary to carry out stress relief construction to eliminate the stress abnormality caused by the thermal expansion and cold contraction of the rail. Finally, long-span steel beam bridges generally have expansion adjusters to adjust the expansion and contraction of rails.