Q. Segmentally lined and Sprayed Concrete Linings tunnels?
The fundamental difference between segmentally lined tunnels and SCL tunnels is that the sprayed concrete in SCL tunnel is employed for temporary linings only. Concrete linings in segmentally lined tunnels are designed with long-term load conditions with adoption of appropriate safety factors. Though the dimension of linings in SCL tunnels is derived from a balance between safety of lining and cost consideration.
The quality of precast concrete linings can be better controlled in precasting yards. It is obviously better than that of sprayed concrete which depends on site workmanship.