Under drainage method for building using perforated drain pipes

Abstract

An under drainage method for building using perforated drain pipes is disclosed. Groundwater entering from underground of a building is collected into collecting drain pipes via horizontal drain pipes, which are wrapped with filtering means such as nonwoven fabric, without using a collecting well. The collected groundwater is maintained in a prescribed water level within vertical drain pipes, which are wrapped with the filtering means, or drained to the surface of the earth. The drained groundwater is utilized as domestic water. Therefore, the method can effectively manage the groundwater, is economical as not requiring the installation of the collecting well, and allows to effectively use perforated drain pipes, which are inexpensive.

What is claimed is:  
     
         1 . An under drainage method for building using perforated drain pipes, the method comprising: 
 forming an under-foundation bottom surface for building by excavating the ground and making the under-foundation bottom surface level; digging a drain pipe foundation of prescribed depth and width under the under-foundation bottom surface;    forming a plurality of horizontal drain pipes by connecting perforated drain pipes to each other in a space formed by the drain pipe foundation digging; forming a plurality of collecting drain pipes by connecting perforated drain pipes, which are manufactured in a prescribed shape, to the horizontal drain pipes at the contour of the under-foundation bottom surface; and vertically installing a plurality of vertical drain pipes from the collecting drain pipes to the surface of the earth, wherein the groundwater entering from under the under-foundation bottom surface is collected into the collecting drain pipes via the horizontal drain pipes and then drained.    
     
     
         2 . The method according to  claim 1 , wherein the collecting drain pipes are manufactured by using cross-shaped perforated drain pipes, T-shaped perforated drain pipes, or straight perforated drain pipes.  
     
     
         3 . The method according to  claim 1  or  2 , wherein the perforated drain pipes used for the horizontal, collecting and vertical drain pipes are made in such a manner that filtering means such as nonwoven fabric is wrapped on the outer surface of the perforated drain pipes.  
     
     
         4 . The method according to  claim 1  or  2 , wherein the horizontal drain pipe and the collecting drain pipe are connected through a connection pipe, the connection pipe being formed by cutting the perforated drain pipe in a prescribed length, the perforated drain pipe having a prescribed diameter for inserting the horizontal drain pipe and the collecting drain pipe.  
     
     
         5 . The method according to  claim 1  or  2 , further comprising a step of forming a permeable layer such as rubbles or gravels on an upper part of the horizontal drain pipes.  
     
     
         6 . The method according to  claim 1 , wherein some of the vertical drain pipes are installed under the surface of the earth in a state that the pipes are sealed with stopper and the other of the vertical drain pipes are installed to the surface of the earth without stopper.  
     
     
         7 . The method according to  claim 6 , wherein the vertical drain pipes, which are installed to the surface of the earth without stopper, have a submerged pump therein.  
     
     
         8 . The method according to claims  6  and  7 , wherein a water level detecting sensor and a sensor detecting device are adhered to the vertical drain pipes having the submerged pump, and the submerged pump is automatically operated and drains the groundwater to the outside if water contained in the vertical drain pipe is above a prescribed water level.