Vibro Ground Improvement - The importance of correct application, monitoring, quality control, testing and environmental sustainability

The course will commence with a brief overview of the (insitu) vibro compaction and vibro stone column techniques, their application on large international projects and the available specifications capturing both techniques, including current best practice.

The importance of quality control and testing for both vibro compaction and vibro stone columns, (also for any materials used) will then be explored, including selection of the most appropriate tests for the vibro ground improvement technique being adopted (and prevailing ground conditions); also the frequency at which they should typically be carried out and the interpretation of results. Correction factors applied to testing using CPTu during vibro compaction application in carbonate sands will also be covered.

The requirement for preliminary trials in advance of large vibro compaction or vibro stone column projects in difficult/complex ground conditions will then be addressed, including interpretation of the results, prior to refinement of the vibro ground improvement design and implementation of the main works. There will be opportunity for attendees to engage with some interpretation of test data.

Environmental sustainability in the context of vibro stone columns will also be explored, including opportunities for use of recycled and secondary aggregates in vibro stone columns and the use of hybrid vibro stone column techniques on contaminated sites.

A forensic examination of case histories of poor vibro ground improvement (vibro stone column) performance will follow, adopting a lessons learned approach. Back analysis of such data provides an opportunity for greater insight into mechanisms that patently cannot be examined in successful vibro ground improvement application and also makes an important contribution to the advancement of both design and understanding, in addition to more effectively identifying and managing risk.

There will then be opportunity to engage with a practical workshop exercise where attendees will be required to select the most economic and environmentally acceptable ground engineering solution (from a choice of vibro ground improvement, displacement and replacement piling techniques) to support a highway embankment approach (over soft ground) to a bridge abutment for a river crossing. Design parameters, production rates and costs for the different options will be provided to assist with completion of the exercise. There will also be opportunity for a discussion at the end of the workshop to establish how attendees coped with the exercise and what they learnt from it.

Towards the end of the course there will be a summary/re-cap of what was discussed and opportunity for a question and answer session.