Mr Cathal Colreavy
- In situ soil testing and site characterisation
- Physical modelling
- Offshore geotechnics
- Associate Professor Conleth O'Loughlin
- Professor Mark Randolph
Use of full-flow penetrometers for measuring shear strength and consolidation characteristics of soft ground
Soft ground presents unique challenges to geotechnical engineers; this challenge is underpinned by the difficulty in accurately determining the available undrained shear strength of the soft soil and accurately assessing the rate at which this strength will increase during consolidation. In an offshore setting, the problem is exasperated by the difficulty in obtaining high quality undisturbed samples for laboratory testing. This has resulted in an increased reliance on in-situ tests and in particular penetration testing. The most common type of probe is the cone. However this device suffers from a number of drawbacks. In recent years, the potential for âfull-flowâ penetrometers to solve the major technical obstacle of soft soil characterisation has been demonstrated. This potential has not yet been fully realised and exploited by the engineering community as there are still key unanswered questions surrounding the framework for interpreting penetrometer test data.
This project aims to address these unanswered questions by way of a series of penetrometer tests in a number of soft clay sites, both onshore and offshore. Tests will also be conducted at a reduced scale in a geotechnical centrifuge and the deductions from these tests verified through the complementary full scale field tests. These data, and the associated interpretation within appropriate theoretical frameworks, will provide the confidence to accelerate the use of full-flow penetrometer tests as a standard site investigation tool for soft ground. Ultimately the research will significantly benefit industry by removing much of the empiricism associated with geotechnical design in soft ground, and in so doing, permit more technically sound and economic designs.
- COFS top up scholarship