Followings are the unique benefits of well point system due to which this method is commonly more preferable over other dewatering methods;
Groundwater Management: The main purpose of any dewatering practice is to draw down the water table below the working platform and maintain the depressed level for the duration of the dewatering period.
Area of Application: Well point system is usually most efficient to cover more land area than other as this system cover more area with a constant capacity of 100 m3/h of water, air or water, and air mixture is discharged against a head of 20 meters.
Design Criteria: Well point system gives you a different method to adopt and selection of the most efficient method for your particular job or site.
Technical Background: Dewatering is commonly required on-site when excavations are to extend beyond the subsoil water table. For shallow excavations (up to 4m) wellpoint dewatering is often the most effective method to achieve an adequate drawdown in permeable soils. (i.e. sand, clayey sand, etc.)
Quick Deploy: Well-point systems can be placed on the project site very efficiently and effectively to reduce the downtime of the construction project.
Less Cost: The system of wellpoint method and dewatering equipment can be taken on lease for short and long periods, and individually, to serve the builder’s dewatering requirements.
More Effective: At construction projects where deep well dewatering is not required, a wellpoint dewatering system is an effective and economical way to reduce the level of the water table to the required excavation level.
It is essential to continue pumping once it has started until the excavation is complete. If it is stopped in between, it may prove to be tragic.
In the case of ground consisting of stiff clay, gravel, or boulders, well points are installed in drilled holes, which increases the installation cost.
Wellpoint dewatering system is suitable for lowering water table by 5 to 6 meters only. For deeper excavations, where the water table is to be lowered for a greater depth caisson method required for that particular site.
Circular Well: These are more commonly used shape is circular, as it has high structural strength and is convenient in sinking.
Double-D Wells: They are generally used for the piers and abutments of bridges which are too long to be accommodated on a circular well of 9 m diameter.
Double Octagonal Wells: These are better than the double-D wells in many respects. The square corners are eliminated and bending stresses are considerably reduced.
Twin-Circular Wells: These are two independent wells placed, very close to each other and having a common well cap. the wells are sunk simultaneously.
Rectangular Wells: They are generally used for bridge foundations having depth up to 7-8 m. for large foundations, double-rectangular wells are used.