Drainage Engineering (English, Romanian, Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Nu este ilustrat. 1920 edition. Extras: ...applied is greater than the total that can be used by vegetation and disposed of by natural drainage. The excess waters which pass into the subsoils are held, in part, by impervious strata below and a gradual filling up of the soil spaces results. Water is collected by relief drains through lateral percolation toward them. This lateral flow is sometimes complex in character and may take place through the soil as a mass or through strata of porous materials only. Where the soil is homogeneous in character, the lateral flow through it is necessarily confined to that portion which is higher than the water in the drain. Where it is stratified, water may follow the porous strata through very irregular paths. It may sink below the level of the drain and again be brought up to it, due to the pressure under which it is travelling. In some tight soils the lateral movement of water through them is so slow that drains are required at frequent intervals, in order to draw the excess water out of them. In others it may be effected by tapping porous sand or gravel strata. In the latter case the excess soil water percolates slowly downward to these strata and is carried by them to the drains. Extent of Effect of Drains.--The distance, on either side, that a drain will be effective in reducing the water content of soils depends upon many and variable factors. Among them may be mentioned, depth of drains, source and amount of water to be removed, and character of soils through which percolation takes place. In the discussion of intercepting drains, it has been shown that under certain conditions, the water reaching a given area from an exterior source may be all intercepted and carried out of the soils. In other instances, that which enters an area may be, ..