AN ANALYSIS OF DIFFERENT LATERAL DRAIN DIAMETERS FOR A LARGE SCALE SUBSURFACE DRAINAGE PROJECT

Construction and materials costs are the two principal factors affecting the economic feasibility of subsurface drainage projects. A study was conducted to determine the potential savings in PVC resin if 80 mm OD diameter lateral subsurface drain pipes were used, rather than the traditional 100 mm OD diameter pipes, for a large scale subsurface drainage project in India. Three lateral pipe design alternatives were considered for three sections of the project area, and drainage plans of the 9 design combinations were prepared using AutoCAD. Using 80 mm OD diameter pipe resulted in savings of PVC resin, ranging from 19 to 24%. A combination of 80 and 100 mm OD diameter laterals resulted in resin savings of 20 to 26%. Such savings in resin, compared to using 100 mm OD laterals alone are highly advantageous for a country like India, where the PVC resin must be imported and foreign exchange used for such purposes.