BoreholeML - Plans for future development

Laboratory data (BoreholeML4)

We consider the enhancement of BoreholeML3 for laboratory data. In the near future BoreholeML3 will be enhanced by inclusion of laboratory data. The Federal Waterways Engineering and Research Institute (BAW) of Germany has developed a data model for geotechnical tests which will be merged with BoreholeML3 and result in the next version (presumably called BoreholeML4).

It is intended to expand the current structures of BoreholeML by geotechnical parameters resulting from geotechnical and laboratory tests.

A variety of information is considered in order to obtain the required parameters of the different soil and rock layers for geotechnical purposes. Some of the most important information is listed below:

1. Structure: type of structure (building, dam, slope, etc.), function, main dimensions, loads, foundation depth
2. Laboratory tests: classification, compaction, permeability, compressibility, shear strength etc.
3. Interaction data: simulation and monitoring of the interaction between subsoil and structure

he results of laboratory tests play an important role in the process of evaluating subsoil parameters. A handicap of many geotechnical projects is the small number of samples of the subsoil that can be tested in the geotechnical laboratory. That is, why the data basis is often not large enough for a statistical evaluation and it is subsequently necessary to compare the results with the values of similar subsoil samples. A collection of test results can be very useful for this purpose.

A further motivation for the development of such databases comes from Eurocode 7 Geotechnical design - Part 1 General rules (EC 7-1). The term “comparable experience” has particular significance in EC 7-1. It is defined as “documented or other clearly established information related to the ground being considered in design, involving the same types of soil and rock and for which similar geotechnical behavior is expected, and involving similar structures. Information gained locally is considered to be particularly relevant”. The term is to be found in each section as comparable experience must be taken into account in all geotechnical designs. Comparable experience has a particular part to play in the specification of the characteristic ground parameters used in calculations. It is stated in EC 7-1 that “the selection of characteristic values for geotechnical parameters shall be based on results and derived values from laboratory and field tests, complemented by well-established experience”.

While a great deal of experience on the geology of different locations in Germany is available in the form of geological maps which have been compiled over many decades owing to legal regulations, no such pool of data has yet been compiled from laboratory tests on soil and rock samples. Ground investigations and laboratory tests on soil and rock are expensive so that only the minimum number of investigations stipulated is ever performed. In such situations geotechnical engineering consultants will try to check the few test results available for a project against comparable experience when specifying soil parameters.

The extension of borehole data with the geotechnical values from laboratory tests is very gainfully for the geological and the engineering disciplines. It is expected that there will also be synergy effects on other disciplines. The structures providing the data exchange format will be defined in the Geotechnical Value Markup Language (GeoValML).

Aims of a running project with the Federal Waterways Engineering and Research Institute ( Bundesanstalt für Wasserbau, BAW) are the compilation of the standardised borehole information exchange format BoreholeML3 and the nationwide comprehensive retrieval of borehole data within the Geo Data Infrastructure Germany (GDI-DE) by means of web services.

For this purpose the specific data formats of the federal states will be exported into the exchange format, defined by the BoreholeML3-standard. The future user – companies, public authorities und interested individuals – will have access to these standardised data of the federal states via a public web client, which is an extended version of the eEarth-Client “borehole viewer Germany” (“Bohrpunktkarte-DE”).

Possible interfaces to GroundwaterML will have to be investigated.