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Civil Engineers, planners and contractors aim for direct economic highways, airports and other traffic routes using natural resources as efficiently as possible in their construction: this often means having to build on poor soils and sometimes even to reclaim land. In many cases, the sub-grade is too weak to allow construction to proceed at a normal rate.
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Soft, cohesive soils are very slow to consolidate. 90% settlement often takes 20-25 years without the use of Prefabricated Vertical Drains (
PVD's).
Prefabricated vertical drain (PVD), provides an economical solution to this issue.
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The principle feature of prefabricated vertical drain (Colbonddrain) lies in providing much shorter and highly permeable drainage paths for the dissipation of excess porewater pressure, allowing 90% consolidation in a time period of months, rather than years.