For the purpose of facilitating construction activities, several dewatering techniques are available during excavation operations. The appropriate selection of the dewatering process results in less expense, more efficient operation, and simpler task completion. In order to analyze different methods of dewatering and select the most appropriate one for a certain project, it is necessary to be aware of their qualities and peculiarities. For that purpose, we will talk about several dewatering techniques and how to pick the best one.
Pumping
Pumping is a dependable option in a variety of circumstances and is also the quickest, least expensive, and most efficient dewatering technique.
In a sump, water is gathered and pumped away for disposal in a pit or section of the earth that is deeper than the basement floor. To that end, industrial pumps can transfer the liquid safely and swiftly while giving total control over where water is released without changing the way the land was formed. There are many different kinds of pumps that can accomplish the task, but the sort of pump you choose will depend on the circumstances in particular. It is crucial to emphasize once more that you must be careful not to ingest slurry, sediments, mud, and other contaminants in dewatering applications since these substances can damage dewatering pumps.
Well point system
This approach is simple to implement, somewhat affordable, adaptable, and useful in the majority of soil and hydrologic situations. Pumps are inserted into the wells that have been dug around the building site. This technique works well in sand and sand-filled gravel, making it perfect for structures with deep basements. The dewatering principles for wellpoints and deep wells are fairly similar. A group of little wells called “wellpoints” are dug all around a particular location to suck out groundwater.
Deep wells
Dewatering can be accomplished by digging deep wells in rocks or soils with permeabilities ranging from moderate to high when a deep excavation is necessary and a significant amount of groundwater has to be extracted. Water may be drained from deep wells up to 24 meters. Depending on the site circumstances, the pumps’ capacity as well as the quantity, depth, and distance of deep wells may change.
Eductors
A dewatering technique known as the eductor well method is used to regulate pore water pressures in materials with limited permeability properties, including fissured clays or silts. By pumping high-pressure water via eductors located at the bottom of each well, this technique employs the venturi principle to produce a vacuum that aids with drainage.
Flood control
All techniques designed to lessen or stop the negative impacts of floods, caused by things like stormwater and heavy rain, are referred to as flood control. Site managers must be ready for probable site flooding during building, tunneling, or mining operations by storing pumps that can transport large volumes of water at low head pressure close by. The same is true for canals with higher water levels, which might have a significant effect on nearby towns if their roads and homes flood. Municipalities must have effective flood protection and be ready to respond promptly when necessary.
Factors that influence the selection of the dewatering method
Excavation type
When dewatering is to be done in a ground region with a lower water level, a traditional well point technique is proven to be both inexpensive and secure. Deep well systems can be utilized for dewatering if the water needs to be reduced to a depth of 30 feet.
When dewatering calls for penetrating permeable soil or rock, a deep well dewatering technique is the best choice.
Type of soil
The dewatering method is usually chosen based on the kind of soil and the local geological parameters. If the soil in the region is homogenous, deep sand, it may be possible to apply the well point approach. Well points need to be built near together if the soil is highly layered and there is a layer of rock or clay that is impermeable. Deep wells or well sites can be placed sparingly wherever the soil needs them to relieve artesian pressure.
Unwanted water on a building site may endanger your project’s safety, raise expenses, and cause delays. Therefore, it is crucial to adopt the appropriate approach to regulate, manage, and remove water when getting ready to excavate the surface or carry out dry site building operations. Due to the fact that geology and hydrology will differ from one site to another, this becomes even more crucial. When choosing the optimal dewatering technique for the building site, we hope that this post will be helpful.