Vertical Drains Research Papers

Accelerate the drainage process and consolidate saturated clay soils is important to achieve stability of the construction. Vertical drains, with a suitable grid and depth, the result of shortening the path of water flow inside the soil... more

Accelerate the drainage process and consolidate saturated clay soils is important to achieve stability of the construction. Vertical drains, with a suitable grid and depth, the result of shortening the path of water flow inside the soil and soil consolidation rate increases from several years to several months. Sombar earth dam, a case study, in Gholaman village in North Khorasan province, Iran, is used to provide agricultural and drinking water in the area. The recent paper shows a comparison between the results of Sombar dam stability with vertical drains of two different materials using the Mohr-Coulomb model with the aid of GeoStudio 2012 computer software. The drains materials are sand and geotextile and the investigated parameters are permeability ratio (ky/kx), drains geometry and time of the dam construction. The results are presented as ratios, settlement ratio (SSAND/SGEOTEX) and safety factor ratio (FSSAND/FSGEOTEXT). The results revealed that there are clear increases in the consolidation settlement ratio, but, slightly increase in safety factors ratio using sand drains comparing to the geotextile. The ky/kx has a clear effect on settlement and factor of safety in sand drains. 1. Introduction Soft clay has a low bearing capacity and high compressibility features. Thus, it is necessary to apply improvement techniques prior to construction to avoid unacceptable differential settlement [1]. To increase the soft soil shear strength, using vertical drains for preloading of soft clay is one of the common methods, in addition, to control its post-construction settlement. Various types of vertical drains were adopted and have been studied, including gravel piles, geosynthetic vertical drains and sand drains [2, 3]. Consolidation time can be reduced from about 1 to 5 years without a vertical drain to about 50 days with prefabricated vertical drains (PVDs) [4]. The efficiency of the vertical drainage method is a function of their distances, depth and diameter of the boreholes and more efficiency in alloys with horizontal permeability exceeding vertical permeability [5]. Depending on scaled model tests, the using of PVDs is successful for the improvement of ultra-soft with increasing in the undrained shear strength and a substantial amount of pore pressure dissipation [6]. The Mohr-Coulomb models (MC) are simple and easily determinable model parameters in numerous engineering applications and the stress-strain response depends on the liquid limit value [7]. The linear elastic-perfectly plastic model (or MC) is one of the most commonly used pressure-sensitive constitutive models [8]. It is necessary for a two-dimensional (2D) finite-element analysis with the plane-strain model to convert the system of vertical drains into an equivalent drain wall [9].

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- by Nagaraj HB and +1
  Sridharan A
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- 4
  Civil Engineering, Expansive Soils, Clays, Vertical Drains

Mumbai is the region consisting of soft compressible marine clay deposits. There are several construction problems on such soils and thus ground improvement is need to be carried out. Vertical drains is generally preferred technique as... more

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- by IJAET Journal and +2
  Chinmay Joshi
  Anand Katti
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- 3
  Consolidation, Vertical Drains, Soft Compressible Clay

BeauDrain vacuum consolidation has been used for the accelerated consolidation of a 7.5m thick very soft soil layer consisting of peat and clay underneath a new 10.5m high embankment near Amsterdam, the Netherlands. The requirement for... more

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- by Jeroen Dijkstra
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- 5
  Vacuum, Consolidation, Vertical Drains, Peat Bogs

Small important details, or lack of details, of the current testing procedures for the testing of the buckled discharge capacity of prefabricated vertical drains can have a large influence on the measured discharge capacities. It is shown... more

In the recent years a sound, GPS based, logging system has been developed by Cofra B.V. The logging system is used for the registration of, amongst others, the drain coordinates, push forces at selected intervals and maximum depth of the... more

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- by Jeroen Dijkstra
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- 2
  Ground Improvement, Vertical Drains