The In-situ Experimental Study About Fast-speed Construction Technology Of Tunnel Invert

In this paper, the long and large railway tunnel which geologic environment of its surrounding rock is complicated during the tunnel being constructed is studied, in order to control the heavy deformation of the surrounding rock and construct tunnel quickly, the in-situ experimental is made about the invert of the tunnel which combined by dry concrete and precast reinforced concrete slab, the construction technique of it is studied too.Now, increasing parallel heading and inclined shaft are the main method to construct the tunnel quickly, if the invert of tunnel is combined by dry concrete and precast reinforced concrete slab, it could increase the safety when the tunnel is being constructed and the invest would be lower than before. The technique is adopted at construction scheme of invert, when we begin construct the invert, deposit smaller slump concrete first, then lay precast reinforced concrete slab on it. Make well use of the characteristics that this type concrete strength increase quickly and its deformation is small by forced, and between two tapping time (2-3 hours), the trucks can go through it, so it shorten curing time of the invert concrete, provide the fast passage for the trucks and attain the fast-speed construction purpose.Through in-situ experimental, the paper gives the thickness, reinforcement, and geometrical modeling of the precast reinforced concrete slab. According to the normal work arranging, it gives the most short time between two tapping slag. At last the finite element method is used to analyze and verify the conclusion. The thesis thinks the technique that the invert is combined by dry concrete and reinforced concrete slab is economical and available, it is important to the construction safety and the whole degree of construction progress of long and large tunnel.