High-performance foam concrete for seismic-isolation materials of tunnels

Protecting the lining of the tunnel with high intensity by coating materials is an effective way to reduce seismic damage. In order to produce a type of economical and reliable seismic-isolation material, an orthogonal experiment on foam concrete is performed. The main factors influencing the seismic-isolation property and the optimum mixture ratio of foam concrete are obtained, and a new type of high-performance foam concrete is developed. The static and dynamic tests results show that the strength, ductility and watertightness of the foam concrete are significantly improved. Besides, in order to check its seismic-isolation property, the high-performance foam concrete as filling materials of Galongla tunnel in Tibet is simulated by FEM. The simulated results show the high-performance foam concrete can remarkably decrease the stress and the plastic zone in final lining, so it can effectively reduce the seismic damage of the tunnel. Considering the seismic-isolation property and low price of high-performance foam concrete, it is a good reference for the anti-seismic design of tunnels in high intensity zone.