History of pavement design

The research on pavement design began in the early 20th century and has a history of more than 80 years. At present, there are dozens of design methods used in various countries. In the early days, empirical method was the main method, which was established according to the results of road test or general observation of roads. It has certain conditions and geographical restrictions, but it is still used in many countries because it is simple and can solve practical problems. With the development of mechanics and mathematics and the application of computer, the stress and deformation in multi-layer pavement structure can be calculated according to elastic theory or viscoelastic theory (see pavement mechanics calculation). With some tests and investigations, theoretical methods have been gradually established and become the development direction of pavement structure design methods, and have been applied in the United States, the Soviet Union, China and other countries.