| 摘要 |
PURPOSE:To obtain a drainage pipe of high filtering action draining underground water efficiently, by burying a underground porous drainage pipe the circumference of which is covered with bottom ash produced after coal combustion. CONSTITUTION:An open channel 2 is provided in soil layer 1, and a underground drainage pipe 3 is arranged in the open channel 2 at a given depth, and a porous pipe unit of an unglazed ceramic pipe or the like is used for the drainage pipe 3. In the circumference of the drainage pipe 3, a bottom ash layer 4 consisting of bottom ash produced after coal combustion is laid, and the upper portion of the drainage pipe is covered with the bottom ash layer 4, and the lower portion can be covered also with a gravel layer, and the pipe is covered with a bottom ash layer in the whole circumference. The bottom ash is limited to 50mum-10mm. by grain size and 5X10<-4>-6X10<-3>cm/sec by coefficient of permeability. Thus, underground water is efficiently drained and the underground drainage pipe also with filtering action can be obtained. |
