MENU

Geophysical methods for studying the operation of embankments

Gemstone will develop a geophysical investigation tool for rapid non-intrusive identification of deterioration 'hot spots' in embankments. It will achieve substantial cost savings and avoid failures that are costly for the economy and society.

More than 500,000 km of embankment are used in Europe for transport and flood defence, representing a 1 billion euro infrastructure asset base, which supports and protects the economy of Europe (e.g. property worth some 2,000 billion euro is protected from flooding). Presently the state and performance of these embankments can only be investigated visually or by slow intrusive methods (boreholes, etc.). The potential now exists to apply a geophysical investigation tool, originally developed for military applications, for rapid non-intrusive identification of deterioration 'hot spots' in embankments. Better targeting of maintenance interventions using this approach will achieve substantial whole-life cost savings and avoid failures costly for the economy and society. Geophysical investigation involves generating electro-magnetic (EM) fields and mapping their propagation through soils and structures. The method finds perturbations in the EM fields arising from concealed boundaries or changed materials. Previous tools and approaches have shown limited effectiveness and poor data interpretation accuracy compared with conventional intrusive geotechnical investigation and description methods. Speed has been affected by the need to repeatedly remount transmitters and receivers. The new technology, using the GEM-2 tool, could provide a breakthrough in an area of science in which infrastructure managers and engineers have been highly sceptical. Preliminary trials suggest the tool could identify soft spots and water leakage paths in embankments. GEMSTONE is supported by national government asset owners across Europe. The 36-month research project involves: - Developing the system over a range of artificial control situations and on a range of flood and transport embankments. - Developing a supporting expert system and database to collect and analyse the data. - Identifying the most appropriate way of further investigating the identified 'hot spots'. The development of a new technology, the so-called Geophysical Methods Suite (GMS), is therefore proposed to enable rapid, economic and repeatable identification of non-homogeneities (possible points of disruption) in line embankments. The proposed geophysical methodology is especially promising for the identification of problem or weak spots in line embankments for water management and flood defence, where embankments could be subject to rupture under extreme hydrological conditions. Through fairly fast and economical monitoring procedures it should also be possible to use the technology to facilitate the maintenance of line embankments in a state that should prevent leakage and ruptures. As well as being non-intrusive and potentially technically effective, the high productivity of this technology should make it possible to check fairly long sections of line embankments in a relatively short amount of time (about 5 to 10 km per day), whilst maintaining adequate levels of precision. The technology should therefore be much more cost-effective than previously used intrusive methods. What is innovative about the proposed Geophysical Methods Suite? Geophysical investigation involves generating electro-magnetic (EM) fields and mapping their propagation and transmission through soils and structures. It involves noting perturbations in the EM fields arising from concealed boundaries or changed materials. Previous tools and approaches have shown limited effectiveness and poor data interpretation accuracy compared with conventional intrusive geotechnical investigation and description methods. Speed has been affected by the need to remount transmitters and receivers at each new investigation location. However, preliminary trials suggest the tool could identify features such as soft spots and water leakage paths in embankments. Having used the new tool to define the hot spots of an existing embankment system, detailed investigation, maintenance and renewal efforts can be concentrated in a cost-effective way on the critical parts of the embankments. The core part of the methods Suite will be Dipole Electromagnetic Profiling with the unique, brand new and innovative apparatus the GEM-2 (multi-frequency device). Although the first information about a tool like GEM-2 appeared in the 1980s, it was developed in the UNITED STATES for military purposes, and was only made publicly available in 2003, when articles about GEM-2 and its characteristics were published in world science literature. To date, this tool has not been used in any application in Europe. Keywords: floods, dike maintenance, geophysical methods.
Acronym: 
GEMSTONE
Project ID: 
3 658
Start date: 
01-01-2006
Project Duration: 
36months
Project costs: 
350 000.00€
Technological Area: 
Geology, Geological Engineering, Geotechnics
Market Area: 
Engineering services

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.