Soil experiment

An experimental procedure was devised to investigate the effects of the lunar environment on the physical properties of simulated lunar soil. The test equipment and materials used consisted of a vacuum chamber, direct shear tester, static penetrometer, and fine grained basalt as the simulant. The vacuum chamber provides a medium for applying the environmental conditions to the soil experiment with the exception of gravity. The shear strength parameters are determined by the direct shear test. Strength parameters and the resistance of soil penetration by static loading will be investigated by the use of a static cone penetrometer. In order to conduct a soil experiment without going to the moon, a suitable lunar simulant must be selected. This simulant must resemble lunar soil in both composition and particle size. The soil that most resembles actual lunar soil is basalt. The soil parameters, as determined by the testing apparatus, will be used as design criteria for lunar soil engagement equipment

Geofizička istraživanja u rudarskom području bogatom vodom : diplomski rad

Geophysical research was performed in the opencast mine, the Hinterburg quarry of the Diabaswerk Saalfelden GmbH in Austria, because it already has a long history of slope problems as a result of complex structural geological conditions and difficult water conditions. According to previous research in this area, there are Paleozoic metamorphic and sediment rocks, basaltic eruptive and overlaid Quaternary alluvium moraine material. Using electrical-resistivity tomography method and seismic-refraction method, the lithological and structural relationships in the subsurface were determined as well as presence of water and its influence. Four electrical profiles (p1, p2, p3, p4) and two seismic profiles (P1 and P4) were measured. Electrical measurements were performed by multi-electrode geoelectrics using GeoTest software and resistivity models were obtained by DC2DInvRes and Res2dinv software. Seismic refraction measurements were performed using Summit X One technology and seismic velocity models were obtained by Rayfract software. The models obtained coincide well and they indicate a big diabase unit and metamorphic rocks together with sediment rocks and clastic moraine material. Wide range of resistivities is due to fractured rocks, caused by numerous faults, which are saturated with water that contributes the resistivity reduction.Geofizička istraživanja provedena su u rudarskom području Hinterburg, u kamenolomu tvrtke Diabaswerk Saalfelden GmbH u Austriji, u kojem već duže vrijeme postoji problem klizanja terena kao posljedice složenih strukturnih geoloških uvjeta i problema s procjeđivanjem vode. Prema dosadašnjim istraživanjima, na ovom području nalaze se paleozojske metamorfne i sedimentne stijene, bazaltni eruptivi te kvartarni aluvijalni morenski materijal. Metodama električne tomografije i seizmičke refrakcije utvrđeni su litološki i strukturni odnosi, kao i prisutnost vode te njezin utjecaj. Izmjerena su četiri električna profila (p1, p2, p3, p4) te dva seizmička profila (P1 i P4). Rezultati električnih mjerenja provedeni su pomoću višeelektrodnog sustava koristeći GeoTest softver, a modeli otpornosti dobiveni su pomoću softvera DC2DInvRes i Res2dinv. Rezultati refrakcijskog seizmičkog mjerenja provedeni su pomoću Summit X One tehnologije, a modeli seizmičkih brzina dobiveni su softverom Rayfract. Modeli se u velikoj mjeri podudaraju i ukazuju na veliko dijabazno tijelo te metamorfne stijene zajedno sa sedimentnim stijenama i klastičnim morenskim materijalom. Širok raspon otpornosti uzrokovan je brojnim rasjedima koji stijene čine razlomljenijima te time pogodnim za infiltraciju vode koja doprinosi smanjenju otpornosti stijena

Development of Harmonized Indicators and Estimation Procedures for Forests with Protective Functions against Natural Hazards in the Alpine Space

The present study was developed in the context of Regulation (EC) 2152/2003 on the monitoring of forest and environmental interactions, the so-called "Forest Focus" Regulation. The specific objective of this study was to explore the possible contribution of the national forest inventories (NFIs) to assess protective functions of for-ests in the alpine space. Key components of protective functions could be determined with the help of on-going national and international studies and processes. In order to grant consistency, definitions of forest area, dam-age potential and hazard potential had to be harmonised. Based on those, a strategy for monitoring and report-ing aspects of protective functions of mountain forests in the alpine space was proposed. Estimation procedures based on existing NFI data and field assessments and their integration in different remote sensing techniques were tested for harmonised monitoring. Final results are presented in this report.JRC.DDG.H.7-Land management and natural hazard

Visão geral dos sistemas de avaliação automática on-line em matemática

Este artigo faz uma revisão sistemática da literatura que trata dos sistemas de avaliação em linha a partir de uma perspectiva instrumental. O contexto em que estes sistemas são implementados é analisado: país, nível educacional, disciplina matemática, e características dos sistemas. Juntos, são categorizados em três focos: estudantes, professores e artefatos. Os resultados mostram que existe uma grande variedade de sistemas e que o trabalho se concentra (i) no impacto nos estudantes: desempenho, variáveis socio-afectivas e formas de trabalho; e (ii) nos artefatos: atributos do artefato, características do artefato cujo utilizador é o professor e características das tarefas mediadas por estes sistemas

Comparison of genetic and tabu search algorithms in aerodynamic design of S-ducts

Confronto delle ottimizzazioni di un diffusore aeronautico utilizzando due diversi algoritmi: tabu search e un algoritmo genetico

Photogrammetrical UAV-based investigation of torrents

Debris flows are a major hazard in mountainous regions. Cost-effective, long-term studies of debris flow torrents, however, are rare, leading to considerable uncertainties in hazard mitigation methods. Here, we address the question if cost effective remote sensing techniques can be applied along the hazard assessment of mountain torrents and further to gather accurate, long-term information on the evolution of the catchment. Active torrents prone to debris flows are often devoid of vegetation and hence can be well captured with photogrammetrically derived methods based on uncrewed aerial vehicle (UAV) surveys. The possibility of automatic extraction of torrent parameters from high resolution terrain models, such as cross-section area, gradient, etc., is investigated. The presented methodology yields continuous and automatically derived parameters along the torrent, which is a major advantage compared to discretized field surveys. Cross-validation thereof with field measurements show strong congruence. Those parameters are highly accurate along sharply incised sections with strong limitations along sections with steep adjacent slopes and/or dense vegetation. A further important result of this work is that multiple UAV acquisitions enable a highly accurate mass-balance characterization of watersheds. After a successful co-registration, the M3C2 algorithm provides valuable results, from which debris flow events can be back-calculated and thus support the determination of site-specific model input parameters. A complete debris flow hazard assessment procedure - missing in current guidelines - is presented. We show that such assessments strongly benefit from UAV data and a subsequent automated parameter extraction: The original point clouds allow to obtain a first overview of the torrent. Derived parameters provide further insights such that key sections and weak spots can be identified and precisely evaluated in the field. The study highlights that the extraction of the true location of the ground poses the key challenge. We show that photogrammetric routines are severely limited by dense vegetation. We find that UAV data can contribute to a comprehensive, reproducible, and objective assessment of torrent processes and predispositions. However, ground-truthing fieldwork remains essential and further research on remote sensing supported hazard assessment of debris flow prone torrents is highly indispensable

Long-term Performance of a concrete-lined Tunnel at CERN

This research aims to investigate the long-term performance of an existing concrete-lined tunnel at CERN, called TT10 tunnel, entirely excavated in the molasse region, in Geneva. Particularly, the study aims to develop a good understanding of the long-term tunnel lining deformation mechanism when its tunnel drainage condition changes many years after construction. To this end, field monitoring and finite element analyses have been conducted.At the world’s largest physics centre for nuclear research (CERN) under controlled laboratory conditions, two high-energy particle beams travel close to the speed of light around the most powerful particle accelerator ever built. The accelerator runs through a deep network of underground tunnels and caverns. To forefront the boundaries of experimental physics, CERN physicists rely on civil engineers to keep their systems running efficiently, performing repairs and upgrades when necessary. However, due to ageing of CERN underground infrastructure, certain amounts of cracking and swelling-induced heave have developed at certain sections along the tunnel linings, which could potentially result in structural damage of the existing infrastructure with consequent impact on the performance of physical experiments. Furthermore, the long-term groundwater seepage has caused the deterioration of the drainage system, inducing a change in the flow regime around the tunnel. This inevitably introduced a new loading condition to the lining, which may have affected the tunnel stability with time. This thesis focuses on the long-term investigation of a horseshoe-shaped concrete-lined tunnel excavated at CERN, in Geneva, in a weak sedimentary rock called the red molasse, an irregular and heterogeneous rock mass comprising a sequence of marls and sandstones. Such complex ground conditions in addition to a change in groundwater and tunnel drainage conditions especially after the large seepage flow event in the year 2013 have contributed to additional loading to the tunnel lining and consequently led to cracks, water infiltration and other structural distress after tunnel construction. To improve the understanding of the long-term tunnel lining performance, a detailed analysis of the field data measurements was undertaken. Both conventional and innovative monitoring technologies were deployed in order to assess the tunnel lining deformation mode with time and also to evaluate the feasibility of different monitoring instrumentation in CERN radioactive environments. The observed data show that compressive and tensile strains develop at the tunnel crown and tunnel axis respectively, suggesting a vertical tunnel elongation with time as the tunnel lining mechanism of deformation. Yet slow development of strains with time was observed, albeit over a relatively short monitoring period of three years. Additionally, noteworthy peak strain values seem to be localised along the lining when the very weak marl units with swelling properties are encountered. In order to validate the field data and to assess the ground loading on the tunnel lining, a series of soil-fluid coupled 2D finite element analyses has been conducted with a particular interest in the effect of change of lining permeability into the lining response. The FE findings show that the tunnel lining permeability relative to the surrounding rock plays an important role on the tunnel deformation mode during the long-term. In particular, the layering divisions in the complex molasse region greatly affect the earth pressure distribution on the tunnel lining and hence results in critical tunnel damage (e.g. cracks and heaving at the tunnel invert). The consolidation-induced structural damage in addition to a reduced capacity of the drainage system with time, in turn, creates a new drainage tunnel lining condition around the tunnel circumference which exacerbates further tunnel distress with time.CERN: European Centre for Nuclear Research - 3 years funding/ sponsorship EPSRC: Engineering and Physical Sciences Research Council - University Fees UCB University of Berkeley, California - 4th year fundin

Modeling of a soft sensitive marine silty clay deposit for a landfill expansion study

An in situ testing program and finite element modeling of Presumpscot Formation glaciomarine clays in South Portland, Maine was undertaken as part of a landfill expansion feasibility study. The very soft sensitive silty clay foundation soils have been monitored during the 20 year lifespan of the landfill facility by an array of settlement platforms, inclinometers, piezometer clusters and periodic field shear vane tests. During this time large horizontal displacements have been observed at a discrete elevation corresponding to a zone of reduced undrained shear strength. Proposals call for a vertical expansion at the site above existing landfill cells. While this proposal will require field corroboration that sufficient strength gain of the foundation soils has occurred to maintain minimum safety factors, a preliminary estimate of future strength conditions will aid the planning and design processes. An in situ testing program consisting of piezocone, field shear vane and dilatometer profiles was performed along with laboratory testing of undisturbed samples to determine the geotechnical properties of the landfill foundation soils. These properties were then used with historical data to create two-dimensional finite element models of the landfill, and to simulate waste loading rates over the lifespan of the facility. The models were then used to project the strength properties and behavior of the soil as additional waste is placed in the proposed vertical expansion. A comparison between historical data from the site and the modeling results demonstrated that the finite element models provide a good indication of the current behavior of the foundation soils with regards to the changes in pore pressure and magnitude of settlement due to loading. While the finite element soil behavior model did not work well in the zones of large displacement; results demonstrated that the calculated increase in undrained shear strength based on the dissipation of excess pore pressure closely matches the changes observed in field shear vane tests during the past ten years throughout the remainder of the profile. The conclusions drawn in this research program is hoped to provide useful information for the site engineer, as well as a strong basis for continuing research.*

The evolution of mountain permafrost in the context of climate change:: towards a comprehensive analysis of permafrost monitoring data from the Swiss Alps

In the Swiss Alps, permafrost occurs discontinuously and commonly has a temperature close to 0 °C. A reduction of Alpine permafrost area and volume is expected in the course of atmospheric warming, but to date, limited evidence is available for Alpine permafrost degradation. Permafrost warming or thaw is accompanied by structural changes in the subsurface, which endanger infrastructure by increasing kinematic activity or slope instability. Changes in the permafrost impact sediment transport to the valley bottom as well as gravitational natural hazards such as rock falls, landslides or debris flows. For these reasons, the quantitative analysis of past and potential future changes in the Alpine permafrost is of great interest and importance. The objective of this PhD project was to investigate observational data from the Swiss Permafrost Monitoring Network PERMOS using an interdisciplinary approach and to develop new methods for the homogenisation and quantitative analysis of long-term monitoring data. The main focus was on assessing changes in the energy fluxes at the ground surface as a function of the snow cover, as well as on evaluating permafrost response to different meteorological conditions and events. This PhD project was part of the research project The Evolution of Mountain Permafrost in Switzerland (TEMPS, 2011-2015), which used combined observational and model-based approaches and aimed at improving the consistency and completeness of permafrost monitoring data. One achievement of this PhD thesis consists of the development of data processing algorithms for filling data gaps in temperature time series and the quantification of resulting uncertainties. Moreover, algorithms for the approximation of the thermal insulation effect of the snow cover based on ground surface temperature (GST) data were developed. This was of particular importance because snow information is usually not available for the points of interest. Furthermore, possibilities for estimating temperature variations at depth based on GST data were evaluated. The information obtained about the propagation of the thermal signal into the ground led to new insights into the temperature dependency of rock glacier creep, which were supported by observational data. Data from more than 20 study sites were made comparable in order to quantify differences at the site- and the regional scale. The GST variability proved to be almost as high at the site scale as at the regional scale. This was explained by heterogeneous topo-climatic conditions as well as by the variable snow cover in the geographic context of the Swiss Alps. The roughness of the terrain played a key role, since it modifies the thermal insulation effect of the snow. Coarse-blocky terrains require more snow to be thermally insulated from the atmosphere and freeze more rapidly compared to smooth ground surfaces. The seasonal GST pattern showed that differences among sites and years were large in early winter, whereas GST were less variable in the summer season. Many locations showed similar snow conditions and therefore similar seasonal and inter-annual GST variations, which could not be explained by variations in air temperature. Although no overall increase in GST was found, the data indicate persistent warm conditions at the ground surface since 2009. Ground temperatures (GT) experienced an overall warming trend down to several tens of m depth over the past 10-25 years. This warming was most distinct in relatively cold permafrost with temperatures below -1 °C. Since the GT at depths between 10-30 m influences the kinematic activity of rock glaciers, the surface deformation rates of the majority of the observed rock glaciers reached maxima between 2013 and 2015. Surface deformation rates quantified by photogrammetry for selected rock glaciers showed an increase in the order of 200-600 % compared to 1990-1995 and 400-800 % compared to 1960-1980. Long-lasting warm conditions at the ground surface were identified to be the cause of the rise in ground temperature and the increased kinematic activity of rock glaciers. Compared with air temperature, where direct effect on the ground is limited to the snow-free period, the snow cover and its onset in early winter had a much greater influence on the heat and energy exchange at the ground surface. After one or two snow-poor winters, permafrost was able to regenerate thermally. Strong ground cooling occurred between 2005 and 2007, which caused a temporary trend reversal in the warming ground temperatures, limiting the effect of the particularly warm air temperatures between June 2006 and May 2007. Since Alpine permafrost is not in equilibrium with the current climatic conditions, recovery periods of efficient winter cooling will probably play a key role for its future evolution and preservation. Overall, the results of this PhD project contribute to an improved process understanding and put observed ground thermal and kinematic phenomena in the context of past and potential future changes of permafrost in the Swiss Alps

Cone Penetration Testing 2022

This volume contains the proceedings of the 5th International Symposium on Cone Penetration Testing (CPT’22), held in Bologna, Italy, 8-10 June 2022. More than 500 authors - academics, researchers, practitioners and manufacturers – contributed to the peer-reviewed papers included in this book, which includes three keynote lectures, four invited lectures and 169 technical papers. The contributions provide a full picture of the current knowledge and major trends in CPT research and development, with respect to innovations in instrumentation, latest advances in data interpretation, and emerging fields of CPT application. The paper topics encompass three well-established topic categories typically addressed in CPT events: - Equipment and Procedures - Data Interpretation - Applications. Emphasis is placed on the use of statistical approaches and innovative numerical strategies for CPT data interpretation, liquefaction studies, application of CPT to offshore engineering, comparative studies between CPT and other in-situ tests. Cone Penetration Testing 2022 contains a wealth of information that could be useful for researchers, practitioners and all those working in the broad and dynamic field of cone penetration testing