Quick clay mapping by resistivity – Surface resistivity, CPTU-R and chemistry to complementother geotechnical sounding and sampling

This study has been carried out with the purpose to investigate how surface resistivitymeasurements, geotechnical CPTU-R soundings and knowledge about the soil chemistry can contribute to a more complete picture of the presence of quick clay. The intention was to compare and complement surface resistivity measurements with cone penetration tests with resistivity measurements (CPTU-R) and measurement of the total penetration resistance, which gives the total skin friction along the rods, together with bothgeotechnical and chemical analyses on the specimens in the laboratory.

Waste unacceptable to landfills for hazardous waste

(1) Direktiv och förordningar; (2) Deponering av avfall; (3) Metod; (4) Resultat; (5) Alternativa sätt att omhänderta eller behandla kritiska avfal

Mapping of quick clay using geoelectrical imaging and CPTU-resistivity

Quick clay has a major impact on landslide risk and it is therefore of considerable interest to map its presence and extent. In Sweden, quick clay has been involved in most landslides in soft clay with serious consequences. The predominant method for detection of quick clay in Sweden has been to take undisturbed samples and to perform fall-cone tests on the clay in its undisturbed and remoulded state. Originally deposited in saltwater in a marine environment, the salt maintains the stability of the clay. When the salt is leached out, the clay can become quick. When salt is leached from clay of marine origin the resistivity increases. In this study the intention was to calibrate electrical imaging with cone penetration tests with resistivity measurements (CPTU-R) and measurement of the total penetration resistance, i.e. the total rod friction, together with both geotechnical and chemical analyses on specimens in the laboratory. The results show that electrical imaging can be used for separation of leached soil volumes in marine clays that may form quick clay, from those where the salt content remains too high for this. In the dry crust and thin weathered zone at the top, the resistivity is high but the clay is non-quick. Also soils with less clay content will have higher resistivity without being quick. The technique may thus be used as a screening tool in order to delimit areas where further investigations are needed from areas that do not require more attention. This has a potential of saving significant resources if used in a relatively early stage of the survey process. It can also increase the overall quality and reliability of the survey results. The induced polarization (IP) results are consistent and seem to be geologically realistic, and appear to contain additional information to the resistivity that is related to material or electrochemical properties, although it is not clear how due to lack of sufficiently detailed reference data. The electrical imaging gives a general picture of the variation in resistivity along soil sections. The CPTU-R gives variations at depth with very high vertical resolution in one specific location. There is generally good agreement between the models based on electrical imaging and the CPTU-R. The CPTU-R results may be used to calibrate the electrical imaging results with quick clay estimations based on rod friction

Mapping of quick clay using sounding methods and resistivity in the Gota River valley

For a long time, the predominant method for detection of quick clay in Sweden has been to take undisturbed samples and to perform fall-cone tests on the clay in its undisturbed and remoulded state. In connection with a large stability investigation covering both sides of the Gota River, from the lake Vanern to the city of Gothenburg, the usefulness of CPTu and static pressure sounding for mapping of quick clay was studied. Evaluation of the correlation between the slope of the penetration force and the presence of quick clay was done within two areas of this investigation. In addition, a separate study was carried out with the purpose to investigate whether surface resistivity measurements together with sounding, using a CPTu-R with measurement of the total penetration force, in combination with fallcone tests and chemical analyses in the laboratory could give a more complete picture of the presence of quick clay

Matrix decision support tool for evaluation of environmental, social and economic aspects of land use

(1) Matrisverktyget; (2) Arbetsprocessen; (3) Arbetet med matrisverktyget; (4) Råd och tips vid tillämpning; (5) Utveckling av resultat och process; Bilagor: (1) Grundmatriser: Matris 1 - Matris 4 http://www.swedgeo.se/upload/publikationer/Varia/pdf/SGI-V612.xls (2) Ett exempel på hur det matrisbaserade beslutsverktyget kan använda

Environmental impact assessment of biofuel production on contaminated land - Swedish case studies

(1) Selection of cases; (2) Normal Swedish Salix Vinimalis cultivation procedure; (3) Scope: The methods and what they measure; (4) Inventory Karlstad oil pepot; (5) LCA-impact Karlstad oil depot; (6) Inventory Fagervik; (7) LCA-impact Fagervik; (8) Carbon footprint calculations; (9) Carbon footprint results; (10) Discussion and interpretation; Appendices: (1) Detailed inventory for Karlstad oil depot; (2) Detailed inventory for Fagervi