Engineering Geology Mapping

Engineering Geology MappingP.M. Maurenbrecher (Docent)Department of Applied Earth SciencesSection Engineering GeologyEngineering Geology Mapping has been central to engineering geology research since the youthful days of the section since the early eighties. Its objectives are such that the project continues to develop and investigate methods for obtaining data and “mapping’ this data to be suitable for the needs of civil engineering and environmental assessments. Much work is being done with increasing cooperation from geophysics to obtain, through non destructive methods, not only an accurate picture of the subsurface but also to obtain the properties of the subsurface from the acoustic signal. The annual fieldwork with students in Spain, though falling under education, increasingly is being combined with research, especially in examining the subjectivity of the descriptive methods and developing simple field tests.IntroductionCentral to the research in 1999 was the H-SENSE project: H arbours- S ilting and En vironmental Se dimentology: Research Program funded by the European Commission Directorate General for Transport DG VII. Details of the project can be found on the website which now has over 100 pages: http://hjs.geol.uib.no/HSense/ situated at the University of Bergen, one of the participants of the project. The object is to produce a model able to predict sediment and its associated contamination distributions in the harbour environment. TU Delft carried out shallow reflection seismic surveys to provide data for the model in 1998. Much of 1999 “research” consisted of providing the data in a proper format for the sedimentation model. Continuation of other activity is the dualistic concept of combining research with teaching as many engineering geology mapping projects have resulted from the annual fieldwork programme with fourth year students from TU Delft and diploma engineering geology students from ITC in Spain. The last millennium year turned out to be subjected to both tragedy and rejoicing with the passing away of the originator of the mapping project Prof. David Price and the tragic and fatal accident of the student, Taco Wever. Taco had produced and published the report for TU Delft’s contribution to the H-SENSE project as his MSc thesis. That year did see the appointment of the new professor, Dr. A.K. Turner, who had inspired the project years earlier for an intensive workshop meeting at Santa Barbara, California on 3D mapping methods. After his appointment Prof. Turner has certainly not diminished in his enthusiasm for mapping techniques in engineering geology and has already made significant contributions towards generating new research possibilities.H-S ENSE does make sense?Officially th e project’s final date was 31 December 1999, though as with all research, research generates new research. The project has been extended up to the end of March 2000 when the final report will be submitted. Several reports, required by the EU DG VII Transport were produced for 1999. Up to the end of 1999 the following reports had been produced: Deliverables D1 to D5, Progress Reports P1 to P3, MSc Thesis/TU Delft Report HSENSE (Wever,1999), a paper: Maurenbrecher et al (1999), an article: Maurenbrecher (1999a) and website publishing: though officially published early 2000 much of the remainder of 1999 was spent making provisions to share the Chirp seismic reflection data (analogue output) with the other participants. Ideally the digital data in SEG-Y format would be more relevant but such data requires large storage and is not suited, as yet, for interactive display in a web-site environment. As a stop gap measure it was found necessary to make back-up copies of the analogue print-out rolls by simply scanning the roll section by section. All the rolls are now scanned and for the Bergen harbour the scanned images are linked to the navigation traverses of the survey vessel. (Gothenburg is in progress). Seehttp://hjs.geol.uib.no/hsense/publications/public/bergen/chirp-archive/chirp-profiles.html the interpreted files given in Wever 1999 have also been transferred to Nottingham and are used as basis for the harbour sedimentation model. The data within the files needed sorting and re-definition before making them more amenable for the sedimentation model. Details of the model are in H-SENSE Deliverable No. 5 report.H-S ENSE- hence-forth?Two meetings were held with the participants in 1999, one hosted by TU Delft in January 1999 and the other by Nottingham Trent University in November 1999. By January 1999 a considerable amount of sampling data had been collected and tested and the first distribution maps of contamination started to appear and the upper sediment distribution maps based on thicknesses, soil type and soil parameters such as density and porosity were being finalised. One EU requirement in such projects is to apply the methods and techniques developed from the research to industry. In January Rotterdam Harbour Authority (Havenbedrijf Rotterdam) took the H-SENSE group on a tourthrough the harbour on board their public relations boat which offered a good opportunity to introduce the aims of the H-SENSE project. Discussions are now ongoing with Rotterdam to apply the modelling techniques using the Rotterdam Harbour database and to develop seismic reflection techniques to determine the strengths of the near-suspended sediments within the Delft Cluster framework and future EU projects.Associated with H-SENSE, a study was initiated on the Maas River project using data from Chirp seismic reflection data. The reason was to both apply spin-off knowledge from H-SENSE, strengthen the net-work of Chirp users and researchers, and to further develop processing of the acoustic signal to determine sub-bottom physical parameters. Significant cooperation from the geophysics section ensures a better understanding of the Chirp capabilities. This work was as good as concluded late 1999 (draft MSc J.W.Bierman).On firmer groundA study in the north of the Netherlands has been completed using stochastic methods to determine causes in variation of bench-mark settlement velocities (Cheung, 1999). The fieldwork teaching-research dualistic approach data-base is growing significantly. Examination of the data has not been actively pursued and, hopefully, during lax intervals between the other project this aspect will receive more attention. Simple, relatively crude, field tests continue to be tried, are becoming more refined in their methods and in some instances, such as the dynamic penetration test correlations are being made with the cone penetration test. An initial trial near Delft has produced promising relationships which, till then, have been completely missing in the literature (Maurenbrecher, 1999b). One MSc (ITC) has been completed on making a study of CPT-SPT correlations on carbonate soils of the United Arab Emirates. A significant conclusion from this study is that earlier correlations for quartzitic sands should probably be much more variable (Akca, 1999).Future ambitionLittle opportunity allowed itself to write two books planned for 1999 on stereographic methods in rock slopes and foundations and marine engineering geology (see CTG volume 1998). The readership is earmarked for the student but should also serve for use or guidance in practice. The option to build up sabbatical leave days introduced in 1999 may finally offer an opportunity to allow this ambition to come to fruition. Prof. David Price unfortunately did not complete the book he was writing on engineering geology. A committee has been formed under guidance of Dr. Mike de Freitas, Reader in Engineering Geology at Imperial College of which the mapping project has been asked to finalise a number of chapters together with a number of other participants a.o. Dr. R. Hack of ITC.ReferencesPaper:Maurenbrecher, P.M., Wever, T.P., Whiteside, P. and Ng., S.K.C. 1999 Acoustic surveys of harbour area se diment processes and properties, in Geotechnical Engineering for Transportation Infrastructure (Ed. Barends, F.B.J., Lindenberg, J., Luger, H.J., de Quelerij, L. and Verruijt, A.) Proceedings 12th Eur. Conf. On Soil Mechanics and Geotechnical Engineering, Balkema, Rotterdam, ISBN 90 5809 0477 Vol 1 p 631-637Articles:Maurenbrecher, P.M. 1999a, Chirp bepaalt sedimentprofielen, Land + Water No 6 p41-43Maurenbrecher, P.M. 1999b, TU- en ITC-studenten testen sonderingstechnieken op Rijswijkse Golfclub, Green Vliet, 12e Jaargang Nr. 4 p36-37Maurenbrecher, P.M. 1999c, David Price: Last farewells? Newsletter IngeoKring, Nr.8 p 11-12 Maurenbrecher, P.M. 1999d, Taco Pieter Adriaan Wever, Newsletter IngeoKring, Nr.8 p 20-22 Maurenbrecher, P.M. 1999e, “A bored but not boring tunnel: Visit to Heinenoord and Lecture, Newsletter IngeoKring Nr.8, p38-43De Bont, J.W.P. & P.M. Maurenbrecher, 1999, Review: Symposium engineering geology and infrastructure, Newsletter IngeoKring, Nr. 8 p32-36Reports/ MSc DissertationsAkc a, N. 1999 Correlation of SPT-CPT data from the United Arab Emirates, ITC MSc Thesis, July, 76p 7 appendicesWever, T.P.A. 1999 Seismic interpretation of H-SENSE data and sub-bottom characterisation using Chirp sonar technology, Memoirs of the Centre of Engineering Geology in the Netherlands, No 177, 43p + 5 appendicesH-SENSE 1999 Progress report P2 9p, 4 appendicesH-SENSE 1999 Progress report P3 8p, 1 appendixH-SENSE 1999 Deliverable D4 Modelling Alternatives p26H-SENSE 1999 Deliverable D5 The environmental sedimentology model: applications and limitations 49p Cheung, G. 1999 Data analyse stabiliteit peilmerken in Friesland, (for NAM) 44p。