Stone Columns
Cost effective Ground Improvement used to strengthen and stiffen poor foundation strata.
Vibro stone columns can provide a highly cost effective ground improvement treatment to strengthen, stiffen and improve drainage in loose/soft ground strata.
The process involves formation of compacted columns of clean granular material, typically coarse gravel, penetrating to depth through the soft/loose strata. The system utilises electric or hydraulic vibrating probes to form a hole in the ground and then facilitate placement and compaction of the granular material to form the column. The vibration probes can be suspended from a crane in the wet process or a bottom feed hollow poker, mounted on a dedicated base rig, offers a dry system option.
The stone column solution has a number of applications which can offer significant benefits on construction projects over poor ground. These include;
- Increased bearing capacity of the ground below shallow foundations and slabs.
- Reduced total and differential settlements of structures.
- Strength and drainage improvement of the ground to limit the effects of disturbance and liquefaction during seismic events.
- Improved uniformity in variable fill or ground strata to limit differential settlements below pavements and hard landscaped areas.
Initially developed in Europe in the late 1930’s the stone column technique and has been used extensively on many of the world’s largest ground improvement projects. The system is particularly relevant where suitable sand or gravel is readily available and large scale site operations easily accommodate the heavy plant used to form the columns.
CMW work closely with specialist contractors who carry out Vibro stone column works and we have the experience and knowledge required to carry out design, specification, testing, value engineering and review processes of stone column ground improvement solutions.