WELLPOINT DEWATERING SYSTEM
Wellpoint dewatering is the process of removal of ground and sub-surface water temporarily from soil in a localized area to complete the construction of a foundation, pipelines or other below ground structures like basements works .
WellPoint dewatering system consists of a series of 2” points to a depth ranging from 5m to max 7 m, which is known as WellPoint. It is installed at a pre-determined spacing (usually at a distance of about 1m to 1.5m around the area to be excavated) using a jetting pump to the depth as per site requirement with enough spacing between each point around the area of excavation. This system of dewatering is most effective for sites given that; it can be used for shallow depths (about 3m to 4m) and for deeper depths (more than 4m and further down) with the application of multi-stage dewatering which invariably makes it the best method for dewatering. It is specially used for trench work for laying pipelines or cable lines from the ground level. However, it can also be used for sewage tanks, fuel storage tanks, and many more. It’s generally used in places where there is a low to medium flow of water.
BEFORE INSTALLATION
MOBILIZATION
BEFORE INSTALLATION
Our system are deployed and installed at pre-determined depth and appropriately spaced along a trench or around an excavation site. The installed well-points, reaches the surface via a riser pipe, which is in turn connected to a header pipe system. It is then discharged away from the site where civil works needs to take place by a high-pressured dewatering pump.
In planning to install or use dewatering, we consider many factors from soil conditions, method of construction and the header elevation to water volume, pump and discharge location etc. Surface drainage and well-point depth is also taken into consideration.
Single stage well-point applications have an effective suction lift from 15ft or 4.6 meters at sea level. Under certain circumstances, lifts can be increased to as much as 20ft or 6 meters.
Our well-point systems dewaters soils, drained by gravity flows with a drawdown limited to an average of 18ft or 5.5 meters per stage; however, several stages may be used in one application or project, depending on the depth required of each operation or project.
Our operations are best suited for excavations stratified soils and permeable sandy soils. We can also dewater coarse sands and gravels, silts and some types of clays. Stratified soils consist of layers of different soil textures. Water does not move uniformly downwards in stratified soils, this is the reason we request for the soil test report on all our dewatering projects.