Prefabricated Vertical Drains (PVDs) or 'Wick Drains' are composed of a plastic core encased by a geotextile for the purpose of expediting consolidation of slow draining soils. They are typically coupled with …Web
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Installation of horizontal drains in slope is one of the common methods used by engineers to lower the amount of excess water in slopes. Horizontal drains could be defined as holes drilled into a slope …Web
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This paper reports the results of dynamic centrifuge tests carried out on sandy models alternatively equipped with vertical or horizontal drains. The main aim of the experimentation was to investigate the use of horizontal drains to mitigate the liquefaction susceptibility of sandy deposits and to validate their applicability as a remediation …Web
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Abstract and Figures. In this study, an interconnected design-chart is developed to design prefabricated vertical drain (PVD) improved ground taking into account the effect of the following ...Web
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By installing sand drains (horizontal or vertical) along the slope, the groundwater level can be lowered below the critical level, reducing the pore water pressure and also the probability of ...Web
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It is known that rainwater infiltration is crucial for rainfall-induced slope failure because the infiltrated water can significantly weaken the shear strength of unsaturated soil. Horizontal drains are commonly used to provide appropriate drainage for the rainwater that percolates out of a slope. However, the effects of the length and location of the subsoil …Web
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The numerical study suggests that the optimal length of the partially penetrating drains (75-80% of the full penetration) would be efficient in aiding sufficient vertical consolidation of the soft ...Web
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Horizontal drains could be defined as holes drilled into a slope and cased with perforated metal or slotted plastic linearly to drain out groundwater [1, 2]. ... "Horizontal drains to stabilize clay slopes," Canadian Geotechnical …Web
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Prefabricated vertical drains (PVDs) have been used extensively to accelerate the consolidation rate of dredged slurry. While some fine particles from dredged slurry can easily squeeze through the ...Web
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A total length of 2392 m of subhorizontal drains were installed, consisting of 21 drains with lengths varying from 24 m to 201 m. The drains consisted of 38 mm diameter schedule …Web
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This study describes the behavior of embankments stabilized with prefabricated vertical drains installed in soft clay foundations, based on several fully instrumented case histories selected from Thailand and Malaysia. A multidrain analysis is conducted based on an equivalent, plane strain model developed by the authors. The deformation of soft clay …Web
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One of the most effective options to stabilize landslides is to reduce the amount of water they contain by installing horizontal drains. A new type of horizontal drain material, …Web
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Horizontal drains are commonly installed to draw down water levels in slopes to add stability. They do this by unweighting the slope material and reducing unwanted excess pore pressures as described in Section 7.1.1 (Figure 7.13).Horizontal drains are generally the best alternative when the depth (or distance into a slope) to desired dewatering is great …Web
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Introducing the prefabricated horizontal drains (PHDs) into the permeable geotextile tubes has been reckoned as an efficient and economical method of dewatering slurries with high water contents. However, its application is limited by the poor understanding of the fundamental consolidation mechanism, often resulting in overconservative designs. With …Web
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View All Drainage View All Drainage. Roof Drains. Floor Drains. Cleanouts. Carriers & Fixture Supports. Floor Sinks. Backwater Valves, Traps & Primers. Stainless Drains. …Web
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Some of the test results are presented in this paper. The study shows that PVDs are effective in consolidating the sludge and binder mixtures, provided that the PVDs used can sustain large bending and resist corrosion by the chemicals in the sludge. Key words: consolidation, geoenvironmental, land reclamation, prefabricated vertical drains.Web
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The design of horizontal drains can be carried out by using numerical analyses or easily by adopting design charts available in literature (Di Maio et al.1988, Desideri et al. 1997, Pun & Urciuoli 2008). ... Canadian Association of petroleum producers (2004). "Planning Horizontal Directional Drilling for Pipeline Construction", Guideline ...Web
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Horizontal drain has usually been applied to lower groundwater table and to ensure slope stability for a long time. It was initially developed for road construction …Web
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In this study, a small-scale physical model with full instrumentation was set up and used to measure the full consolidation process of a cylinder of clay with one prefabricated vertical drain (PVD) in its middle. The model test produced several interesting phenomena: (i) a delayed pore-water pressure increase under a constant pressure during loading stages, …Web
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Therefore, the influence factor ( I q ) would be determined according to the location (Fig. 2), by the following equation: 1 x y [15] Iq 2 ( x b) a R1 Design Procedures for Linear Variation of Horizontal Permeability in the Smear Zone Most design procedures for vertical drains use horizontal time factor (Th) vs. degree of consolidation curves ...Web
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United States. Pacific Palisades. Martinez Formation. N34°00'00" - N34°00'00", W118°15'00" - W118°15'00". Abstract. Horizontal drains have been …Web
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3. Theoretical modelling for soft ground consolidation via vertical drains and vacuum preloading: multi-drain analysis. A unit cell theory for vacuum consolidation including a single drain assuming equal strain was proposed by Indraratna et al. (2005a).The obvious constraint of this single drain analysis is that it cannot successfully …Web
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This paper presents an experimental investigation on the feasibility and effectiveness of an improved method for dewatering sewage sludge (SS) in landfills. Compared with traditional vacuum preloading with prefabricated vertical drains (PVDs), an improved intermittent vacuum loading with wheat straw vertical drains (WSVDs) was …Web
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from field measurements. The field measurement results indicated that horizontal drains were indeed effective for lowering water table and for increasing the stability of the investigated slope. Therefore, horizontal drains are considered to be a useful and economical method for improving the stability of residual soil slopes against rainfall.Web
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3. Results and Analysis 3.1. Calculation and Analysis of Vertical Settlement Displacement. Figure 3 is the final settlement calculation cloud chart of vacuum combined surcharge preloading with two different drainage plates. It can be seen from the figure that whether PVDs or PHDs are used, the settlement deformation of the soil layer from top to …Web
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Planar and horizontal drainage is a useful technique to consolidate soils weakened by the presence of water. Removing the water, by inserting a suitable drainage path can provide long-term improvements …Web
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Horizontal drains have been used on western Colorado highways for several years, in both preconstruction and postconstruction applications. In specific cases, horizontal drains have proved to be cost·effective in preventing and cor recting failures in cut-and-fill slopes. The use of horizontal drains has been limWeb
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A computer program named "BSSDS" is developed for large-strain EVP consolidation analysis of clay layers with vertical drains, taking into account the complicated in situ conditions, such as resistance of vertical drains, smear effects, variation of permeability with void ratio, and multilayered soils.Web
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Offshore Vertical drains. Since the development of the synthetic prefabricated vertical drain (PVD) in the late 1970ties, Cofra is worldwide one of the leading contractors in this segment. Cofra has installation rigs available for each soil type, varying from very soft soils to very stiff intermediate layers that can be deployed on pontoons.Web
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The design approaches to prefabricated vertical drains (PVDs) for different geotechnical and geoenvironmental engineering applications involve converting the PVD's rectangular band shape to an equivalent circular shape to simplify the analytical analysis. Several equivalent diameter equations for PVDs are available in the literature. However, …Web
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Hansbo, S. (1960) "Consolidation of Clay, with Special Reference to Influence of Vertical Sand Drains," Proceedings No. 18, Swedish Geotechnical Institute, Stockholm. Google Scholar. ... "A New Technique for Reduction of Excess Pore Pressures During Pile Driving", Canadian Geotechnical Journal, Vol. 11, No. 3, pp. 423–430. Crossref.Web
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