PREVENTION OF SOIL COMPACTION IN THE CONSTRUCTION OF HORIZONTAL TUBULAR DRAINAGE BY THE TRENCHLESS METHOD

Abstract

In the article the analysis of the main constructive solutions forreducing the compaction of soil in the near-drain zone at theconstruction of horizontal drainage from pipes by drainage plows isgiven. The trenchless installation is promising in the construction ofdrainage systems, especially taking into account its significantadvantage over the trench-type way of productivity and labor costs.The experience of Europe, Africa, Asia, and America indicates a lowercost using drainage plows with a construction drainage depth of 1.3 to1.4 meters, which is explained by a much higher rate of insertion. Inthe Netherlands, at depths of drainage from 1.0 to 1.2 m anddiameters of pipes to 0.08 m, the difference is from 15 to 25%.However, the advantage of this method of insertion decreases rapidlywith increasing depth of insertion of drainage and increase of the resistance of cutting of soil.However Drainage Straight Leg Plow at more crytical depths willresult in soil compaction in the walls and bottom of the crack, whichreduces soil watertightness in these zone and adds additionalresistance to inflow water in the drains. The review gives examples ofboth existing drainage-plows of different countries and promisingdevelopments in this direction. It was shown that the Mastenbroek VPlow drainage guide avoids soil compaction and creates favorableconditions for inflow water in drains. This is due to the loosening ofthe soil above the drain, increasing its volume with the bulging on theday surface and the absence of soil compaction zones by redirectingcompression forces from the horizontal to the vertical plane.The V-plow can insert pipes with a maximum external diameter,including protective-filtering material, from 0.10 to 0.125 meters. TheV-plow in different soils (semi-unstable, in medium textured and finetextured soils) allows you to obtain better indicators than the usualdrainage plows and drainage trenchers. However the advantage oftrenchless installation decreases rapidly with greater drain depth andwith higher soil resistance. It works best in clay loam and clay, worsein sand.