MANUAL
Soil drainage with the wellpoint system lacks specific technical literature despite being widely applied in civil and industrial constructions. There is still little research carried out in this field by universities and technical institutes, although there is a vast bibliography on the behavior of groundwaters subjected to pumping (Dupuit, Theis, Darcy, Chapmann, Engelund etc.). Almost everything that exists today about this drainage method is based on the experiences of manufacturing and user companies. This can be understood from the following considerations:
- The sizing of a wellpoint system for its safe use is generally done on the basis of practical experience gained by analogy while working on a wide range of construction sites.
- All the existing theories are not useful to investigate the soils at issue, since they don’t have the usual characteristics of isotropy and homogeneity. It would be necessary to introduce corrective coefficients that are difficult to detect and unreliable.
- The investigations for the detection of the parameters required to mathematically satisfy certain relationships, would not find any justification in the normal use of wellpoint systems. Until recently, it was thought that the wellpoint system was usable only in sandy soils (medium permeability), while it is currently used also in loamy and clayey soils (low permeability), in gravelly ones (high permeability), in soils with waterproof stratifications and, in some cases, even rocky ones. In the feasibility study of the constructions in the presence of an aquifer, drainage with the wellpoint system is undoubtedly the first in the applicability ranking considering its simplicity, versatility and cost-effectiveness. In the following pages we’ve have collected the technical and practical considerations deriving from the execution of numerous drainages in the most varied stratigraphic and logistic situations.