Ground
Engineering properties
Determination of the elastic properties of the ground, including strength and stiffness.
Geophysical survey can generate the larger picture for designing overall foundation treatment and type. Furthermore, it can isolate smaller detail, pinpointing localised areas of weakness to help determine the most effective spatial arrangement of piling.
Geophysical techniques (mainly seismic-related) can provide an alternative to intrusive methods for characterising ground properties across many types of site. As one of the world’s leading oil and gas exploration organisations, Fugro has an enviable capability in seismic technologies, and engineering clients involved in onshore geotechnical investigations can benefit from the technologies and expertise within the group.
Investigation may be conducted from the ground surface using seismic refraction, reflection or multi-channel analysis of surface waves (MASW). Alternatively, geophysical methods may be deployed downhole on cone penetration testing (CPT) equipment or within boreholes.
MASW is perhaps the most valuable method for determining ground properties, the seismic velocities derived from MASW can provide geotechnical information such as Poisson’s ratio and a useful estimate of the rippability of the ground can be determined from P-wave refraction data. In other words, MASW gives engineers essential data on ground bearing capacity and can help groundwork contractors decide how much excavating ‘muscle’ they need to move earth.
Results take the form of a map of mechanical properties, identifying stronger and weaker ground strata which can inform the design of foundations.
Typical applications include predicting ground behaviour in the event of loading. e.g. piling, and construction activity, monitoring compaction of earthworks, hazard assessment and supporting the extractive industries, for example by predicting ground rippability.
