Equivalent Diameter of Vertical Drains with an Oblong Cross Section

Equivalent diameter of a prefabricated vertical drain

“…(2). Moreover, it can also be observed that the experimental results reported by Suits et al (1986) are in acceptable agreement with the equivalent diameter equations proposed by Atkinson and Eldred (1981), Long and Covo (1994), and Eq. (2).…”

“…The results show that for a constant PVD width, varying the thickness of a PVD has insignificant effect on the total PVD flow rate (Q) whereas varying the PVD width and keeping the PVD thickness constant affects the total PVD flow rate. The flow rate contributions of the PVD width (Q w ) and thickness (Q th ) to the total PVD flow rate Hansbo (1979) deq ¼ 2ðw þ tÞ=P Long and Covo (1994) deq ¼ 0:5w þ 0:7t Atkinson and Eldred (1981) deq ¼ ðw þ tÞ=2 Fellenius and Castonguay (1985) deq ¼ ð4ðwtÞ=PÞ 0:5 w is the prefabricated vertical drain (PVD) width and t is the PVD thickness. (Q ¼ Q w þ Q th ) were determined as shown in Fig.…”

“…The Hansbo (1979) equation is based on the surface area of a PVD. Long and Covo (1994) used an electric analogue approach to develop their equation. The Atkinson and Eldred (1981) equation takes into account throttle that takes place close to the drain.…”

Reevaluation of the factors influencing the consolidation of ground by incorporating prefabricated vertical drains

“…Table 3 also shows that the ratio k h /k s was proposed between 1.34~10, which was obtained from laboratory and field measurements. This value is also determined depending on the soil Hansbo (1979Hansbo ( , 1981Hansbo ( , 1987 6.62 cm Atkinson and Eldred (1981); Jansen and den Hoedt (1983); and Rixner et al (1986a, b) 5.20 Fellenius and Castonguay (1985) 2.26 Pradhan et al (1993) 4.41 (d e = 1.13×1.5 = 1.695 m) Long and Covo (1994) 5.28 …”

Theoretical and Numerical Perspectives and Field Observations for the Design and Performance Evaluation of Embankments Constructed on Soft Marine Clay

“…From the finite element studies, Rixner et al (1986) proposed that Pradhan et al (1993) suggested that the equivalent diameter of band-shaped drains should be estimated by considering the flow net around the soil cylinder of diameter d e ( Figure 6). The mean-square distance of their flow net is calculated as 4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 More recently, Long and Covo (1994) found that the equivalent diameter d w could be computed using an electrical analogue field plotter:…”