Abstract Tunnel portals are the weak point in the seismic design of tunnels. Based on wave equations of Rayleigh waves, the calculation formula of displacment, acceleration and curvature of the ground are gained, and the seismic fortification length of tunnel portals are discussed. The results show that 1) the displacment, acceleration and curvature of the ground decreased rapidly as the burial depth increased under the Rayleigh wave action; 2) seismic fortification length should be prolonged. In the end, seismic fortification length proposed for tunnel portal is verified by the damage of tunnel portals in the Wenchuan earthquake. The content in the paper may be as a reference to seismic design of tunnels, reconstruction of disarster areas and revision of corresponding codes and regulations.
Abstract：
Tunnel portals are the weak point in the seismic design of tunnels. Based on wave equations of Rayleigh waves, the calculation formula of displacment, acceleration and curvature of the ground are gained, and the seismic fortification length of tunnel portals are discussed. The results show that 1) the displacment, acceleration and curvature of the ground decreased rapidly as the burial depth increased under the Rayleigh wave action; 2) seismic fortification length should be prolonged. In the end, seismic fortification length proposed for tunnel portal is verified by the damage of tunnel portals in the Wenchuan earthquake. The content in the paper may be as a reference to seismic design of tunnels, reconstruction of disarster areas and revision of corresponding codes and regulations.
SUO Ran-Xu-1,
WANG Yan-Yan-2
.Seismic Fortification Length of Tunnel Portals under Rayleigh Wave Action[J] MODERN TUNNELLING TECHNOLOGY, 2011,V48(4): 13-18
2011, Vol. 48 