Single Stage Well Point System Of Dewatering

3 well point systems a.

Single stage well point system of dewatering.

Well point systems a well point system consists of a number of well points spaced along a trench or around an excavation site all connected to a common header which is attached to one or more well point pumps. Single stage system b. Where excavations are too deep for a single stage wellpoint dewatering system sld pumps and power offer a multi stage rental solution. Point m is 2m to the east of point z.

Point u is 6m to the east of point t. The single stage well point system of dewatering an excavation can be used if the depth of excavation does not exceed a 5 m b 10 m c 15 m d 20 m. In case of a multi stage well point system care should be taken that the header of the lowermost stage is not more than 4 m above the excavation bed so. Point z is to the south of point t.

The spacing of dewatering system is depends upon nature of soil condition and ground water table. Multistage well point system these systems are used if excavation exceeds 4 5 m and there is a chance of slope failure. The single stage well point system of dewatering an excavation can be used if the depth of excavation does not exceed a 5 m b 10 m c 15 m d 20 m. The area to be dewatered is surrounded by number of well points.

Multible stage system c vacuum system 4 chemical grouting 5. Point r lies on the line formed by joining. Sometimes a single stage well point system is attached with jet eductor pump this system allows dewatering up to 25 to 30 m depth. Sld s wellpoint dewatering systems have the ability to deal with very low flows in silty sands to much larger flows in coarse sands and gravel.

Minimum spacing is 1m. This method is suitable to soils having coefficient of permeability between 10 2 to 10 4 cm sec. However eductors ejectors require only a single stage to effect drawdowns of up to 100 feet. By single stage well point stage method the water table is lowered by about 4 5m.

Point r is 5m to the north of point m. Well point assemblies made up of a well point screen riser pipe and swing joint with tuning are generally installed by jetting. This is preferable over a multi stage well point system.