AS 8700-2011

This Standard provides general requirements for the execution, testing, supervision, monitoring and installation methods of prefabricated vertical drain projects. It also includes information on design considerations, and practical and design aspects of vertical drainage.Prefabricated vertical drains are used for the improvement of low-permeability, highly compressible soils, and in on-land and marine constructions for-(pre)consolidation and reduction of post-construction settlements; speeding up the consolidation process by decreasing the path lengths for pore water dissipation;increasing soil stability (by increasing effective stresses in the soil);groundwater lowering; andmitigation of liquefaction effects.In each case there is an overall treatment of the soil (the volume of the drains is small in relation to the soil volume treated).Prefabricated vertical drains may also be combined with other foundation or ground improvement methods (e.g. sand drains, vacuum consolidation, electro-osmosis, piles and compacted sand piles, rigid inclusions, dynamic compaction and deep mixing).See References 1, 2, 3 and 4 in the Bibliography.Guidance on practical aspects of prefabricated vertical drains, such as investigation of drain properties, execution procedures and equipment, is given in Appendix A. Guidance on the evaluation of soil characteristics and design considerations is given in Appendix B.

First published as AS 8700-2011. First published as AS 8700 - 2011.