DOUBLE FLOOR DRAINAGE SYSTEM FOR TUNNEL

A drain system of a double floor plate for a tunnel is provided to improve stability of a road pavement structure, and to reduce construction period by reducing the construction process. A drain system of a double floor plate for a tunnel includes a drain layer(110) having an auxiliary base layer or an antifreeze layer spread on a tunnel floor, a drain plate(120) having an upper block installed in an upper part of the drain layer by longitudinally and horizontally spacing blocks, a column part tapered from a lower part of the upper block and extended downward and latticed drain passages formed in the lower part of the upper block by the space with sides and front and rear parts of the tapered column part, a lean concrete layer(130) charged in the block of the drain plate, and a pavement layer(140) formed in an upper part of the lean concrete layer. The column part is longitudinally extended by rounding front and rear parts, or collecting the front and rear parts into an apex, or forming streamlined front, rear and side parts.