In this project about 700.000 meters of wickdrains (prefabricated vertical drains-PVD) were specified. Working with sand drains need more time and work. The soil should be consolidated quickly, and the road is near the sea. It was like draining the sea. At the top of the soft soil a sand layer was placed to move the machines and also for drainage. The contractor preferred a ...
In this project about 700.000 meters of wickdrains (prefabricated vertical drains-PVD) were specified.
In this project about 700.000 meters of wickdrains (prefabricated vertical drains-PVD) were specified.
In this project about 700.000 meters of wickdrains (prefabricated vertical drains-PVD) were specified.
In this project about 700.000 meters of wickdrains (prefabricated vertical drains-PVD) were specified.
I think the first project that the wickdrains have been used was in Belgium, in the Brussels Metropolitan Transport system. The second may be the Eskisehir light rail tram system. Actually the main application of PVD's are in soil consolidation. But in this tram project it was used to collect the leakage water to prevent not to pass the lower section to cause rusting. So, ...
PVD’s have high discharge capacities, typically 30 x 10-6 m3/sec to 90 x 10-6 m3/sec compared to a Ø 0.35 sand drain with a discharge capacity of 20 x 10-6 m3/sec (Van Santvoort, 1994). When installed with purpose designed mandril, smear effects are much smaller for PVDs than for the large diameter sand drains. Zone of smear is directly proportional to the diameter of mandril ...
where: t = consolidation period (years) D = diameter of drained soil cylinder (m) d = equivalent diameter of drain (m) Ch = horizontal consolidation coefficient (m2/year) Uh = average horizontal consolidation degree
d = equivalent diameter of PVD b = width of PVD
1)triangular spacing standard 2)for a square grid : D = 1.128 S S : spacing of drains D : diameter of the equivalent cylindrical column of soil, drained by each drain. For more information about the calculation of prefabricated vertical drains (wickdrains) please also see other posts.