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

Chapter 8 GROUND IMPROVEMENT
Table of Contents
Table of Contents .................................................................................................................... 8-i
List of Tables ......................................................................................................................... 8-ii
List of Figures ........................................................................................................................ 8-ii
8.1 INTRODUCTION .......................................................................................................... 8-1
8.2 SOIL IMPROVEMENT TECHNIQUES ............................................................................... 8-2
8.2.1 Removal and Replacement .............................................................................. 8-2
8.2.2 Surcharging ................................................................................................... 8-3
8.2.3 SUB SURFACE DRAINAGE IMPROVEMENT SYSTEM ........................................... 8-3
8.2.3.1 Vertical Drainage System ................................................................. 8-4
8.2.3.2 Sand Drain System .......................................................................... 8-5
8.2.3.3 Prefabricated Vertical Drain (PVD) .................................................... 8-5
8.2.4 Vibro-Floatation ............................................................................................. 8-6
8.2.4.1 Vibro Compaction ............................................................................ 8-6
8.2.4.2 Vibro Replacement (Stone Column)................................................... 8-7
8.2.5 DEEP SOIL MIXING (LIME COLUMN) ................................................................ 8-8
8.2.5.1 Mix Design ...................................................................................... 8-9
8.2.6 Dynamic Compaction ...................................................................................... 8-9
8.2.7 Some Additional Considerations ...................................................................... 8-10
REFERENCES ....................................................................................................................... 8-12
APPENDIX 8A: DESIGN OF VERTICAL DRAINAGE SYSTEM ....................................................... 8A-1
March 2009 8-i