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Fältgeotekniska undersökningar är en viktig del av geotekniken och används vid nästan alla byggprojekt för att utreda markförhållanden och skapa underlag för dimensionering av konstruktioner. För att optimera grundläggningsdesign önskas ofta flera fältmetoder eftersom metodernas olika tillvägagångssätt kan resultera i skilda resultat och parametrar, vilka tillsammans möjliggör undersökningar i alla tänkbara jordförhållanden. En metod erkänd utomlands för sin höga tillförlitlighet och användningsbredd är pressometern, en metod som är på väg att glömmas bort i Sverige. Syftet med examensarbetet var att studera pressometerns potential och användningsområde i Sverige. Pressometern som metod bygger på radiell expansion och mäter jordens volymförändring genom trycksättning. Förfaringssättet som pressometern belastar jorden på liknar situationen som jorden kommer att utsättas för under byggnation. Pressometerförsök resulterar i metodspecifika hållfastighets- och deformationsparametrar, från vilka särskilda beräkningsmodeller för uppskattning av bärförmåga och sättningar har utvecklats. Målet var att förse svenska geotekniker med en referens för att förhålla sig till pressometerresultat och -modeller. Ett intressant område för pressometern i Sverige är friktionsjordar där ett behov av pålitliga in situ-metoder har identifierats. Beräkningsmodellerna baserade på pressometerresultat har utvärderats och jämförts med beräkningsmodeller för hejarsondering vilken är en vanlig sonderingsmetod i friktionsjord. Vidare har empirisk data från projekt där båda metoderna använts, analyserats och empiriska samband utvärderats mellan dem. Beräkningsmodellerna tolkades sedan mot det empiriska sambandet. Slutligen utfördes ett fältexperiment med de båda metoderna, som tyvärr misslyckades. Dataanalysen visar på ett tydligt empiriskt samband mellan hejarsondering och pressometerförsök, dock grundade sig den empiriska analysen på endast 14 observationer och hög standardavvikelse iakttogs. Beräkningsmodellerna för vardera metod visade sig skilja markant. Gällande beräknad vertikal bärförmåga kunde visas att för konstruktioner med stort relativt grundläggningsdjup beräknas den vertikala bärförmågan högre med pressometermodellen än hejarmodellen. För sättningsberäkningar ger pressometermodellen gynnsammare uppskattad sättning vid ökad plattbredd än hejarmodellen. Sammanfattningsvis visar studien på att pressometern har ett tydligt användningsområde i Sverige med bra beräkningsmodeller men att klara regler och normer saknas och borde förtydligas. Pressometern är en in situ-metod som i praktiken kantas av problem i utförandet men att den teoretiska grunden och behovet av verklighetsnära fältmetoder ändå skapar utrymme för metoden i svenska friktionsjordar.

The main objective of this thesis was to determine how and why peat fails with the aim of reducing the threat caused by this and also for prevention of the occurrence. Peat is a very common soil in both the UK and Ireland so knowing how it fails and how to prevent it is hugely beneficial. To do this three seperate case studies where analysised, all located in Ireland but in different areas, to see if the failure methods had any similarities or differences that could be linked together. The main finding was that therewas not one sole causal factor for all peat slides but instead a combination of different factors; although some factors are more influential than others for example rainfall. A number of solutions where put forward such as a drainage system for the peat slopes and while they are limited, due to most of the factors being of natural origin, they have the potential to reduce the likelihood and frequnecy of failures if properly implemented.

A theoretical and experimental examination into the dynamics of granular solids has been completed which covers aspects of flow and failure within this material. The investigation is divided into three natural sections; each section being devoted to a different type of failure. As indicated by the title, the subject of the study was cohesionless soil, and thus the basic tenets of soil mechanics and the failure of granular media are applicable. The first section deals with gravity flow of non-cohesive granular material in both axial and rectangular geometry. Traditional plasticity theory is used to establish characteristics of stress and strain, also stress sliplines within a wedge. From these, two relationships between the angle of internal friction and the bound to a radial flow field are established. A minimum energy theory of flow is discussed and then used to determine mass flow rates. From this theory a velocity profile is deduced an by use of either the entire profile or the vertical ray or the extreme angular ray three relationships between the bound tot he radial flow field and the mass flow rate are established. The limits to piping in axial symmetry are defined. It is shown that gravity flow in rectangular geometry must always result in pipes. Experiments were devised to substantiate these findings and they show that, dependent upon the assumptions that were made, the devised relationships bracket, within reasonable limits, the radial bound and the mass flow rate. Work of two other investigators is compared wit the presented experimental results. The definitions of pipe are shown to have validity. Section Two was the result of an attempt to measure a parameter that was relevant to the investigation in Section Three. The possibility of the passive rather than the active lateral earth pressure acting upon a shifting retaining wall was discovered while attempting the measurement of the coefficient of friction of sand on mild steel. The third section is concerned with an investigation into the factors that affect the forces on a horizontally propelled model that is immersed in sand. The parameters of depth, speed, projected model area, and other model characteristics were varied, and experimental relationships between the force and these parameters determined. Also, pressure measurements were made within the sand as the model passed to determine the extent of the failure region. Several other experiments, such as the effect of false walls on the force level, were made in order to determine the limits of validity of the main experiment. It was found that the force on the model varied as the 2.3 power of the depth, linearly with the projected model area, and not at all with model surface, model length, or speed in the range 0-15 feet per minute. The pressure measurements and false-walls studies showed that failure occurred within the sand and not at the walls of the tank; also that failure took the form of successive shear dislocation of pyramidally shaped wedges of sand.

Antalet vindkraftverk, både i Sverige och i världen, ökar från år till år samtidigt som de blir allt högre. Utvecklingen mot högre torn och kraftigare turbiner kräver allt större fundament för att klara de krafter och moment som uppkommer. Ofta varierar markförhållandena mellan de olika verkslägena inom en och samma park. För landbaserade vindkraftverk är tre olika typer av fundament vanligast; gravitationsfundament, bergförankrade och pålade. Arbetet har fokuserat på det första och behandlat hur varierande friktionsvinkel samt grundvattennivå påverkar storleken på fundamentet och därigenom produktionskostnaden för fundamenten. Arbetet utgår från olika friktionsvinklar och grundvattennivåer och jämför vilka kriterier som blir dimensionerande och hur produktionskostnaderna påverkas. De kriterier i brottgränstillstånd och bruksgränstillstånd som utvärderats är; risken för stjälpning, allmänt bärighetsbrott, glidning samt differentialsättningar. Vid allmänt bärighetsbrott har två brottmoder utvärderats, dels den ”vanliga” brottmoden ut från fundamentet, dels brottmoder in under fundamentet. Den senare är viktig att utvärdera då stora excentriska laster verkar och visar sig vara dimensionerande i flera fall med friktionsvinkel runt 38 grader och hög grundvattennivå. Resultaten visar att vid höga grundvattennivåer kombinerat med högre friktionsvinklar så blir risken för stjälpning dimensionerande och fundamentet kan inte minskas ytterligare trots att friktionsvinkeln går upp. Resultaten visar även att cirkulära fundament i samtliga fall är mera material- och kostnadseffektiva än kvadratiska. Resultatet visar tydligt att grundvattennivån har mycket större påverkan på hur stort fundamentet behöver vara för att erforderlig bärighet ska uppnås. Då grundvattennivån påverkar fundamentsstorleken kraftigt är det av stor vikt att den undersöks väl för att undvika att överdimensionerade fundament används. I grova drag kan det räcka med två fundament som är placerade på platser med en gynnsammare grundvattennivå (en meter lägre än övriga) för att motivera projekteringskostnaden för en ytterligare fundamentsstorlek. Fundamentets storlek beror även på jordens friktionsvinkel men påverkas i något mindre grad än av grundvattennivån. / The number of wind turbines are increasing in Sweden as well as in the rest of the world. At the same time the business goes towards higher towers and more powerful turbines to increase production of electricity. This requires larger and more stable foundations to handle the forces and moment that the wind generates. Since wind farms often consists of multiple turbines and covers a great area the ground properties varies between the turbine sites. For wind turbines onshore, three different types of foundations are the most common. Gravity based foundations, rock anchored foundations and piled foundations and the selection is based on thickness of soil strata (down to rock), soil type and properties as well as the level of the groundwater table. This thesis examines how variations in friction angle and level of ground water table affects the production costs of gravity based foundations. Different criteria in ultimate limit state and serviceability limit state is checked; risk of overturning, general shear failure, sliding and differential settlements. General shear failure is evaluated with two rupture lines, both outwards from the foundation and inwards under the foundation. The later one is of importance when the foundation is subject to large eccentric loads and turns out to be the critical parameter in cases with friction angle about 38 degrees and a high groundwater table. With higher friction angles (in combination with high groundwater table) overturning is the designing criterion. In all cases the circular foundations are more size and cost effective than square shaped. The results shows that the groundwater table has greater impact on the required size of the foundation compared to the friction angle of the soil. Therefore it’s important to examine the groundwater situation well at an early stage of construction to avoid larger than necessary foundations.

This project is a Master's Thesis which extent is 30 credits in the specialization Soil and Rock Construction within Civil Engineering at the Technical University of Luleå. The project is a laboratory study, which has been executed at the Technical University of Brunswick in Ger-many.The project has looked into how uniaxial strength of stabilised soil is affected when the mate-rial has been exposed for ground frost. The study also checked whether there is a recovering effect in the material after thaw. The study was performed in laboratory by studying two soils and two stabilisation agents. The materials were a clay stabilised with lime and a silty sand stabilised with cement. Both soils where taken from the Stockholm area in Sweden. In total 108 samples were manufactured with different combinations of content of stabilization agent, hardening time, number of freeze-thaw-cycles and curing time. This resulted in 18 combinations of samples for each soil. The questions the project answered are:impact of freeze-thaw-cycles on the uniaxial compressive strengthif the curing after freeze-thaw can repair the material with respect to its uniaxial compressive strength.The results show that the uniaxial compressive strength of the lime-stabilised clay is reduced by about 40 to 80 %. The magnitude depends on the amount of stabilizer, hardening time and freeze-thaw-cycles. The cement-stabilised sand gets a change of its uniaxial compressive strength by ±10 %. Consequently there is no evidence that the freezing has an impact on the uniaxial compressive strength in this case. After curing of the stabilised clay samples exposed to freezing and thawing the uniaxial compressive strength was found to be 20 to 115% of the original value. Therefore, there is only a small actual recovery in the clay samples. For the ce-ment-stabilised sand a more continuous growth of strength was found rather than recovery during the after curing. This was in the range of about 0 to 25%.The cement-stabilised sand has shown to be brittle and sensitive to deformations. This makes its limitation not to be carrying capacity. The limitations are rather deformation and move-ment.

The Skunk Hollow Landslide (located 1 mile north of Mantua, UT along US-89) was instrumented with an automated monitoring system to aid in the determination of the triggering mechanism of slow moving landslides. Data was transmitted wirelessly through telecommunications to allow year-round, real-time monitoring of the site. Measurements were recorded and analyzed for the first season of landslide movement (fall 2009 to spring 2010) to better understand the correlations between snowmelt and movement initiation. Based on the first year of data, it appears that the Skunk Hollow Landslide is controlled by water infiltrating into the slide mass through cracks and fissures. Snowmelt is a function of many meteorological variables and future years of observation will create a better understanding of the interaction of these variables with landslide initiation.

<p>In co-operation with the Geological Survey of Norway, 395 samples of topsoil, 44 bedrock samples and 24 samples of sand from sandboxes at kindergartens taken in Oslo, the capital city of Norway, were analysed for a wide range of elements. To get a measure on the bio-availability of arsenic, a five stage sequential extraction procedure was accomplished on a subset of 98 topsoil samples and on all 24 samples of sand from sandboxes. These fractions (i.e. “Exchangeable”, “Carbonate”, “Reducible substrate”, “Organic” and “Residual”) were analysed for arsenic. Bulk concentrations in a representative subset of 10 bedrock samples were determined by XRF analysis.</p><p>For the concentrations of the elements As, B, Ba, Cd, Cr, Cu, Hg, Mn, Mo, Ni, P, Pb and Zn in soil, geologic sources are important, but human activity has had a large effect on concentrations in topsoil, especially in the central districts. At least 81% of the samples contain more arsenic than the Norm value for polluted soil used by the Norwegian authorities. For chromium, zinc and lead, the percentages are 65, 74 and 25 respectively. In topsoil, up to 50% of the arsenic is extractable in the exchangeable, the carbonate and the reducible substrate fractions, but only 2% of the samples exceeded the Norm value after the three extraction stages. After four stages of extraction, 69% of the samples exceeded the Norm value.</p><p>At 24 kindergartens in the central districts of Oslo, concentrations of As, Cd, Cr, Cu, Ni, Pb and Zn in topsoil samples are higher than in samples of sand from sandpits, but differences in arsenic are low. All topsoil samples and 63% of the sandbox samples exceed the arsenic Norm value for polluted soil used by the Norwegian authorities. Concentrations of at least one of the elements Cr, Cu, Ni, Pb and Zn exceed the Norm value in the topsoil. At two kindergartens all elements, except Cd, exceed the Norm value in the topsoil.</p><p>In the samples from the sandboxes, arsenic concentrations in the exchangeable, the carbonate and the reducible substrate fractions, lie at a higher level than in topsoil samples. Leakage of arsenic compounds from impregnated and painted wood have probably caused elevated concentrations of this element in the sand. At two kindergartens the cumulative arsenic content in samples from the sandboxes exceeds the Norm value of 2 mg/kg As for polluted soil already after two fractions (i.e. the “Exchangeable” and the “Carbonate” fraction). After three fractions, the arsenic content in sand at 5 kindergartens exceeds this value. After four fractions this number was still 5. Regarding soil, no kindergartens had a cumulative arsenic content after three stages of the extraction procedure. After four stages 16 kindergartens contained more arsenic than the Norwegian Norm value of 2 mg/kg As.</p><p>Bulk concentrations of metals, in the bedrock samples, are generally higher than the acid soluble concentrations. Differences are small for copper and zinc, somewhat higher for lead and nickel and considerably different for chromium. Acid soluble chromium concentrations in soil differ little when compared with acid soluble concentrations in bedrock, but are in general much lower than bulk concentrations in rock. Chromium is probably strongly incorporated in the mineral structure of rock samples and concentrated HNO3 cannot solubilize all chromium molecules. For copper, lead and zinc, the acid soluble concentrations in soil are higher than the bulk concentrations in bedrock. The parent rock material cannot be the only source for these elements in soils and various anthropogenic sources dispersed by air or water probably have major influence.</p><p>The enrichment of nickel in topsoil near highways in Oslo might be due to the bitumen content of road dust. The enrichment of chromium and copper might be due to wear and tear of cars and engine parts. There is no enrichment of cadmium and zinc in topsoil near highways. Concentrations of zinc in topsoil in Oslo are generally high, most probably because of industry. The possible addition of zinc from traffic to the topsoil is not observed, in this study.</p>

In co-operation with the Geological Survey of Norway, 395 samples of topsoil, 44 bedrock samples and 24 samples of sand from sandboxes at kindergartens taken in Oslo, the capital city of Norway, were analysed for a wide range of elements. To get a measure on the bio-availability of arsenic, a five stage sequential extraction procedure was accomplished on a subset of 98 topsoil samples and on all 24 samples of sand from sandboxes. These fractions (i.e. “Exchangeable”, “Carbonate”, “Reducible substrate”, “Organic” and “Residual”) were analysed for arsenic. Bulk concentrations in a representative subset of 10 bedrock samples were determined by XRF analysis. For the concentrations of the elements As, B, Ba, Cd, Cr, Cu, Hg, Mn, Mo, Ni, P, Pb and Zn in soil, geologic sources are important, but human activity has had a large effect on concentrations in topsoil, especially in the central districts. At least 81% of the samples contain more arsenic than the Norm value for polluted soil used by the Norwegian authorities. For chromium, zinc and lead, the percentages are 65, 74 and 25 respectively. In topsoil, up to 50% of the arsenic is extractable in the exchangeable, the carbonate and the reducible substrate fractions, but only 2% of the samples exceeded the Norm value after the three extraction stages. After four stages of extraction, 69% of the samples exceeded the Norm value. At 24 kindergartens in the central districts of Oslo, concentrations of As, Cd, Cr, Cu, Ni, Pb and Zn in topsoil samples are higher than in samples of sand from sandpits, but differences in arsenic are low. All topsoil samples and 63% of the sandbox samples exceed the arsenic Norm value for polluted soil used by the Norwegian authorities. Concentrations of at least one of the elements Cr, Cu, Ni, Pb and Zn exceed the Norm value in the topsoil. At two kindergartens all elements, except Cd, exceed the Norm value in the topsoil. In the samples from the sandboxes, arsenic concentrations in the exchangeable, the carbonate and the reducible substrate fractions, lie at a higher level than in topsoil samples. Leakage of arsenic compounds from impregnated and painted wood have probably caused elevated concentrations of this element in the sand. At two kindergartens the cumulative arsenic content in samples from the sandboxes exceeds the Norm value of 2 mg/kg As for polluted soil already after two fractions (i.e. the “Exchangeable” and the “Carbonate” fraction). After three fractions, the arsenic content in sand at 5 kindergartens exceeds this value. After four fractions this number was still 5. Regarding soil, no kindergartens had a cumulative arsenic content after three stages of the extraction procedure. After four stages 16 kindergartens contained more arsenic than the Norwegian Norm value of 2 mg/kg As. Bulk concentrations of metals, in the bedrock samples, are generally higher than the acid soluble concentrations. Differences are small for copper and zinc, somewhat higher for lead and nickel and considerably different for chromium. Acid soluble chromium concentrations in soil differ little when compared with acid soluble concentrations in bedrock, but are in general much lower than bulk concentrations in rock. Chromium is probably strongly incorporated in the mineral structure of rock samples and concentrated HNO3 cannot solubilize all chromium molecules. For copper, lead and zinc, the acid soluble concentrations in soil are higher than the bulk concentrations in bedrock. The parent rock material cannot be the only source for these elements in soils and various anthropogenic sources dispersed by air or water probably have major influence. The enrichment of nickel in topsoil near highways in Oslo might be due to the bitumen content of road dust. The enrichment of chromium and copper might be due to wear and tear of cars and engine parts. There is no enrichment of cadmium and zinc in topsoil near highways. Concentrations of zinc in topsoil in Oslo are generally high, most probably because of industry. The possible addition of zinc from traffic to the topsoil is not observed, in this study.