Volume 6 – Geotechnical Manual, Site Investigation and Engineering ...

Chapter 8 GROUND IMPROVEMENT
Figure 8.11 Relationships between U and Tv
Figure 8.12 Relationship Of Uh and Tv For Horizontal/Radial Drainage
The design of PVD system requires the prediction of the rate of dissipation of excess pore pressures
by radial seepage to
vertical drains as well as evaluating
the contribution of vertical drainage.
The first comprehensive treatment of the radial drainage problem
was presented by Barron who
studiedd the theory of vertical sand drains. Barron works was based on simplifying assumptions of
Terzaghi’s one-dimensional linear consolidation theory. The most widely used simplified solution from
Baron’s
analysis provides the relationship of time, drain diameter, spacing, coefficient of
consolidation and the average degree of consolidation.
8A-2
March 2009