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One issue that must be taken into consideration when undertaking a construction project

on June 09 at 01:16 PM
One issue that must be taken into consideration when undertaking a construction project is the long term settlement and stiffness of the ground such as the soil, clay, or soft silt. The solution to ensuring much quicker soil consolidation and settlement has been the development of Wick Drains. Wick drains are used when there is a problem with soil consolidation.

Also known as Prefabricated Vertical Drains (PV Drains), wick drains are flat, plastic fabric coated channels surrounded by a thin geo-textile filter jacket that functions as a free-draining water channel. The fabric acts as a filter because it maintains permeability while preserving the fine soil particles.

Wick drains reduce the distance water travels to a drainage path thereby reducing the time of settlement. Basically, they act as a free-draining water channel. Wick drains are suitable for peat, silts, clay, silt sands, and sludge waste from industry. Both the core and geotextile filter jacket of wicker drains makes them extremely durable and resistant to chemicals and many micro-organisms such as bacteria.

Wick Drains are a cost efficient method of hastening the consolidation process of fine grained soils in order to cut down on the time for starting construction. It allows for the drastic reduction time for long term settlement to occur. The use of wick drains helps to remove excess water, consolidate the compressible soil, and promote soil settlement. This allows a construction project to start in a few months instead of 12 months or more.

Special equipment called 'Stitchers' are used to install wick drains. The 'Stitchers' are mounted on a crane containing an installation mandrel that holds the wick drain. The mandrel along with the wick drain is driven hydraulically or vibrated into the ground allowing the penetration of rocky soil. When the mandrel is withdrawn, the wick drain remains in the ground. Depending upon the soil RO Water dispenser conditions, the speed of installation can be up to 2,000 feet per hour. As the soil consolidates, it increases in strength because there is a large reduction in water.

Wick drain projects have included: sedimentation ponds, buildings, airport runways, highway embankments, dams, golf courses, large storage areas...etc. The installation of wick drains is essential in areas that contain high fills that have to be positioned over low strength soft soils. The rate of soil consolidation and settlement depends on how quickly the water leaves the soil through the wick drain process. This is largely determined by the size of the spacing between the wick drains as well as the permeability of the water.

The particular design curves of the drain spacing chosen, the fill height, and consolidation time, all allow construction to begin much sooner. The costs of installing a wick drains depends on a number of factors that include: soil conditions, difficulty of pre-drilling, type of drain used, size of the project...etc. There are professional companies that specialize in installing wick drains. Today, the installation of wick drains has become an invaluable component of a construction project that requires a faster rate of soil consolidation and settlement.
 

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