Dewatering at NCS why it works
Why a geo report helps get the system design right time and save money and time. NCS Fluid Handling Systems engineers can help. To be clear, NCS does not charge for dewatering design fees on projects that we are performing the work and with every order you get the entire NCS Fluid Handling Systems team investing into the project’s success.
The two types of flows that are observed, Saturated and Unsaturated, today we are working with the situations and solutions for Saturated Flow.
In a situation where the condition of soil has large and small pores that are filled with water, this is referred to as saturated. A saturated flow takes place when the soil is saturated with the direction of flow from one zone of with higher moisture potential to a lower moisture potential. When dewatering therefore when only pumps are installed inside an excavation the amount of inflow water increases, you are in a sense pulling water into the excavation from outside, in this case a properly designed well- pointing system will reduce or even eliminate the flow of water moving horizontally and vertically into the excavation, but if submersible pumps are incorporated into an excavation, they can keep up with additional mop up.
Water typically percolates down in a vertical fashion into the lower layers. But horizontal flow also occurs at a slower rate typically. It should be noted when reading a geo report that the horizontal movement of water is more evident in the clay type soils, whereas the vertical action of water is much more evident in sandy soils.
There are 5 factors that determine the flow of water in saturated soil:
- Texture, which is the particle size, the bigger the particle the more rapid the flow as noted above in the clay versus sandy soil note.
- Structure, in clay soils with a single-grain structure, the gravitational water percolates slower than in soils that have a granular structure. In a clay like soil structure, that resemble layers or plates the saturated flow is poor whereas in granular structure the flow is much greater.
- Organic matter - Organic matter contributes to the porous structure of the soil and a larger proportion of pore space = greater flows.
- Pressure - Gravitational water flow is also influenced by the resistance offered by the entrapped air in the soil. With an increased number of pockets of air, the soil-air pressure is increased, and water percolation is decreased. In a dewatering application the saturated flow is very important.
The engineered team and the technical support team at NCS Fluid Handling Systems as well as the project managers have significant knowledge and experience in geo-technical report comprehension, engineering analysis and field experience.
Contact the team any time at 1-800-661-7867 to arrange a lunch and learn or have your specific situation explained. The team with provide dewatering solutions that range for custom designed well point pumps or deep well submersible pumps through to sediment control options and ground water treatment. We take dewatering seriously because its what we do full time.