Many different measurement techniques are available for soil investigations. In the weak Dutch soil, road pressure techniques such as CPT probing are quite useful. Drilling always involves sample disturbance, leading to inaccuracies and uncertainties in the measurement results. Road-pressure (CPT) techniques can offer a solution here.
Geotechnical Exchange Format (GEF)
GEF is a general language structure for storing and transferring geotechnical data. GEF procedurally specifies how a new structure should be composed. This provides a basis for a general exchange of geotechnical measurement data. More information about GEF and GEF-related software can be found on Deltares' Public Wiki.
The Public Wiki also contains software for working with GEF files. And conversion programs are available including:
- GEF to Excel
- GEF to NENGEO (working link in the strikethrough text)
There is a dedicated GEF for drilling data, for CPT data and for dissipation tests. They are all developed, published and managed by CUR.
- GEF-BORE Report: for reporting drilling data
- GEF-CPT Report: for reporting CPT data
- GEF-DISS Report: for reporting dissipation test data
Geophysical methods for geotechnical consultants (2015)
This guide helps determine which geophysical techniques are suitable as a method of ground investigation to answer specific geotechnical questions. The structure of the manual is in line with Geo-Impuls / CUR guideline C247'Risk-based soil investigation'.
Opting for modern measurement techniques
A good rationale for choosing modern measuring techniques can be found in an article by drs ing R. Stuut. Theo Edelman also advocates the use of innovative measuring techniques in environmental soil research. In 2003, SKIB published an extensive report on innovative soil investigation techniques.
TU Delft research
TU Delft's digital database contains nearly six thousand research articles from the Faculty of Civil Engineering and Geosciences. The database is kept up-to-date and includes articles published since 1906. Of interest for the topic of measurement techniques are:
Heterogeneity aspects underground
It is difficult to tell from ground surveys themselves whether the picture of the subsurface obtained is complete. Have local variations not been overlooked, for instance, which could have a major impact on a design? Delft Cluster has developed a methodology to rationally deal with these uncertainties. As part of GeoImpuls, the Stochastic Subsurface Schematisation (SOS) was developed.
Semi-automatic interpretation
Delft Cluster has developed three tools to interpret probe results semi-automatically. This makes it possible to rapidly analyse large amounts of data and improve subsurface models.
A guide to cone penetration testing
An informative website from Lankelma with extensive information on CPT probes. Lankelma's website also features an informative list of all kinds of road penetration probes for in situ measurement of geotechnical and chemical parameters. In addition, an introductory film on cone penetration testing can be viewed.
Soil sampling techniques
-Sampling dredging in a canal or ditch bottom requires special techniques because the material is actually 'thick water'. On waterbodem.nl you will find an overview of suitable techniques for this purpose: the Beekersampler, Piston-corer, Valbom, Van Veen happer, Vibro Corer, Suigerboor as well as performing a quantity determination (cubing) are discussed.
Cone Penetration Testing
CPT probing involves pressing a rod with a cone-shaped tip -the probing cone- into the ground at a constant speed of two centimetres per second. By measuring the mechanical resistance of the soil on the cone, one can determine the bearing capacity of the soil. Furthermore, it is also possible to use a CPT probe to measure adhesion, or the friction and adhesion of the soil along the circumference of the CPT cone. To also measure groundwater pressure, an electric cone, or piezocone, can be used. The groundwater pressure test is called CPTU or dissipation test.
Sub-topics
Measurement techniques
Related pages
Construction pits
Foundation techniques
Ground improvement
Underground construction
Road constructions on soft ground