Terzaghi’s theory illustrates the arching effect phenomenon by which the vertical pressure on a flat plate will be reduced as the flat plate moves downward, but without considering the effect of the inclined sliding surfaces below tunnel roofs and roof shapes. Based on Terzaghi’s theory, this paper presents a practical arching theory for two-dimensional arch tunnels in good ground. One concise formula for the vertical pressure on arch tunnels is developed considering the inclined sliding surfaces below the tunnel roof. The shape effect of the tunnel roof on earth pressure is also considered by adopting the empirical values of the total lateral pressure coefficient λ t , which is closely related to the shape of tunnels for the flexible lining. This proposed formula is verified by the upper bound theory while the formula is simpler and more suitable for engineering applications than the upper bound theory. The vertical pressure on arch tunnels calculated by the proposed formula is significantly smaller than that calculated by Terzaghi’s formula. This formula also reveals that there is an interaction between the lateral and vertical pressure on arch tunnels in good ground. The interaction mechanism is discussed and models for soil arches near tunnels are proposed. Finally, the proposed theory provides a good explanation for the experimental results in good ground. The theory is not only suitable for shallow tunnels but also for deep tunnels, and it broadens the understanding of the arching effect from a flat plate to a two-dimensional arch tunnel.

LOKASI: Ruang Koleksi Umum
Rak: 2