Drain board of water flow layer one body type and, method for permanent drain used of that

摘要

PURPOSE: A drain board integrated in a water permeable layer and a permanent drain construction method using the same are provided to set the drain board directly on the final excavated surface without additionally excavating a trench. CONSTITUTION: A drain board integrated in a water permeable layer comprises a drainpipe(110), a water permeable layer(120), and non-woven fabric. The drainpipe is horizontally installed on the reference surface of an excavated sub-foundation. The drainpipe is formed of a frame with front, rear, right, and left sides open and geotextile which encloses the top, bottom, right, and left sides of the frame. The water permeable layer is installed as being pressed against both sides of the drainpipe. The non-woven fabric is unified on the bottom surface of the water permeable layer and the drainpipe.