NATM adopts shotcrete and bolt support as the main means, which can keep up with the excavation face to the maximum extent. Therefore, the space-time effect of excavation face can be used to limit the deformation development before support and prevent surrounding rock from entering loose state. Advance support can be carried out when necessary, and the early strength and comprehensive cohesiveness of shotcrete ensure the timeliness and effectiveness of support.
The correlation is as follows
NATM is the abbreviation of NATM tunnel construction method. The original text is NATM. The concept of NATM was put forward by Austrian scholar Professor ICZ in 1950s. On the basis of tunnel engineering experience and rock mechanics theory, it is a construction method with bolting and shotcreting as the main support means. After many times of practice and theoretical research in some countries, it was put forward in 660.
Since then, this method has developed rapidly in many underground projects in western Europe, northern Europe, the United States and Japan, and has become one of the new technical signs of modern tunnel engineering. NATM was introduced into China in 1960s, and developed rapidly in the late 1970s and early 1980s. It can be said that NATM is indispensable in all key and difficult underground projects, and it has almost become a basic method to build tunnels in weak and broken surrounding rocks.