Journal Papers by Robert H R G K Hack
Simulated microbial corrosion in oil, gas and non-volcanic geothermal energy installations: The role of biofilm on pipeline corrosion
Energy Reports, 2022
The role of biofilm in the Microbiologically Influenced Corrosion (MIC) of carbon steel by Sulfat... more The role of biofilm in the Microbiologically Influenced Corrosion (MIC) of carbon steel by Sulfate Reducing Bacteria (SRB) in oil and gas exploitation, and geothermal installations is investigated. Simulated biofilm made of calcium alginate, abiotic sulfide (to mimic SRB metabolic end product HS), CO2 (to mimic CO2 from SRB dissimilatory sulfate reduction) and simulated brine (3.0 wt% NaCl) are used to simulate the SRB environment. For reference experiments, distilled water is used instead of simulated brine. The electrochemical results show that the simulated biofilm in the reference at 120 min exposure time and in brine experiments neither inhibits nor accelerates corrosion. These results are strongly supported by corrosion kinetic adsorption parameters, statistical T-test, ICP-OES, pH, SEM-EDS and XRD. The results contradict with the existing literature on the role of biofilm and this is likely due to the presence of both HS and CO2 as simulated SRB metabolites. Despite of this discrepancy, the obtained corrosion rates (0.25 to 1.6 mm/year) in the simulated SRB environment are comparable to published corrosion rates obtained in SRB experiments (0.20 to 1.2 mm/year). The results highlight the novelty of this research and have a direct impact on the role of other microbial metabolites on the corrosion of carbon steel.
The influence of chelating agents on clays in geothermal reservoir formations: Implications to reservoir acid stimulation
Geothermics, 2022
Acid stimulation to enhance the permeability of geological reservoirs is the oldest technique sti... more Acid stimulation to enhance the permeability of geological reservoirs is the oldest technique still in use. Acid stimulation sometimes fails due to either poor stability of the acid or due to an undesirable influence on clay minerals in the reservoir formation. Among others, clay minerals in a reservoir formation govern the permeability of the reservoir. The interaction is investigated of biodegradable chelating agents (BCA1, BCA2 and BCA3) and clay minerals kaolinite-natural (KN) and montmorillonite-K10 (MM) in a hydrothermal reactor in which the conditions of a geothermal reservoir are simulated under a CO2 environment with temperature of 230 οC and pressure of 85 bars. The porisimetry, ATR-FTIR and infrared reflectance spectroscopy show changes on surface properties and structure of MM and KN which in turn suggest chemical interaction to take place. However, XRD results show insignificant changes on structure of MM and KN. The ICP-OES, pH, conductivity and salinity results show the chemical interactions (dissolution reactions) to take place on both KN and MM and therefore strongly support the results of the earlier techniques. The results show that BCA1 and BCA3 cause greater dissolution with lower precipitation as compared to BCA2 and no-BCA. Further, the R -values from multiple linear regression show that pH and BCAs’ function groups have strong influence on the normalized concentration of dissolved ions though the p-values are insignificant. The coefficient values show that the BCAs’ functional groups have more influence than pH. BCA1 and BCA 3 would therefore be useful acids for reservoir stimulation in improving permeability especially in geothermal reservoir formations which contain clay minerals.
Ingeokring Newsletter (Dutch association of engineering geologists and geo engineers), 2020
Weathering is the chemical and physical change in time of ground under influence of atmosphere, h... more Weathering is the chemical and physical change in time of ground under influence of atmosphere, hydrosphere, cryosphere, biosphere, and nuclear radiation. Quantities of weathered materi-al do not need to be large to change the geotechnical properties of a groundmass, for example, weathering of discontinuity walls that reduces the shear strength. Weathering is the reason for many constructions and other engineering applications in which ground is used, to become a disaster during project lifetime. Hence, accounting in the design for the degradation of geotechnical materials in the future is necessary to ensure a stable structure for the full lifetime.
Advice on sustainable energy Wells Meer, Bergen (Energielandgoed Wells Meer, gemeente Bergen; Toetsingsadvies over het milieueffectrapport)
Netherlands commission for environmental assessment (NCEA), Nov 27, 2018
De gemeente Bergen heeft de ambitie om in 2030 energieonafhankelijk te zijn, dat wil zeggen dat d... more De gemeente Bergen heeft de ambitie om in 2030 energieonafhankelijk te zijn, dat wil zeggen dat de gemeente dan volledig gebruik maakt van duurzame energie en daarmee voorziet in de eigen totale energiebehoefte. Voor de grootschalige energieopwekking die daarvoor nodig is wil de gemeente het Energielandgoed Wells Meer ontwikkelen. Het Energielandgoedmoet voorzien in 50% van de energiebehoefte van de gemeente Bergen (een energieproductie van 0,87 PJ per jaar). Daarnaast wil de gemeente dat het landgoed ruimte biedt voor recreatie en dat de energiebronnen benut worden voor educatieve doeleinden. De locatie zal in een structuurvisie worden aangewezen. Om de locatiekeuze in de Structuurvisie te onderbouwen, is een plan-milieueffectrapport met een Passende beoordeling opgesteld. De gemeente heeft de Commissie voor de milieueffectrapportage gevraagd over het MER te adviseren.
Malaysian Journal of Remote Sensing & GIS. 4 (2). ISSN: 1511-7049. pp. 94-111., 2015
Landslides are the most frequent type of natural hazards that are often observed in hilly and mou... more Landslides are the most frequent type of natural hazards that are often observed in hilly and mountainous areas. It may lead to not only loss of life but huge economic losses due to property damage, and other indirect effects such as disruption to transportation networks. These effects can be minimised and avoided if landslide prone areas are identified in advance by landslide susceptibility assessment. The main objective of this research is to develop a landslide susceptibility map (LSM) for the northern part of Kota Kinabalu, Sabah based on a statistical quantitative method, the information value method. The LSM was developed based on the analysis of results of spatial landslide distribution and eleven conditioning parameters. The percentage of area classified as relatively high susceptibility (high to very high) to landslides is 35.4%. These areas are mostly located at hilly areas, especially on the northern facing slopes with slope gradient between 25 to 35°. These areas are also located along old main roads (constructed more than 30 years old). Moderately susceptible areas are mostly located at foot hill areas and consist of 20.7% of the total area. Areas with relatively low susceptibility (very low to low) to landslides cover 43.9% of the total area and are mostly located at coastal, river valley and excavated areas. The area under curve (AUC) value is about 0.8022, which indicates the overall success rate of 80.2%. Due to the non-availability of medium scale LSMs for the area at present, the generated LSM map can be utilised to predict the landslide prone areas of the study area. It may also be used by the local authorities and other relevant agencies as a basis tool in land management and future planning for development in the northern Kota Kinabalu area.
In civil engineering infrastructural projects many different parties are involved into different ... more In civil engineering infrastructural projects many different parties are involved into different phases during the lifetime of a construction; that are consultants, contractors, architects, suppliers of subsurface and surface data, governmental bodies, politicians, the client himself, etc. The communication between these different parties is difficult. This is essentially caused by a lack of quality and uncertainty information concerning collected data
Weathering effects on discontinuity properties in sandstone in a tropical environment: case study at Kota Kinabalu, Sabah Malaysia
Bulletin of Engineering Geology and the Environment, 74(2), pp 427-441, May 2015
The formation of mechanical discontinuities (i.e., bedding, joint planes) is one of the main effe... more The formation of mechanical discontinuities (i.e., bedding, joint planes) is one of the main effects of weathering in rock masses. It is also highly important for forecasting the geotechnical properties of a rock mass in the future. The effect is well known in most rock types, but the mechanisms of forming discontinuities and the resulting variation of mechanical discontinuities throughout a rock mass especially in sedimentary rocks such as sandstone in a tropical environment, are often still poorly understood. The aim of this research is to study and understand the discontinuity formation process in a tropical environment. In sandstone in Sabah, Malaysia, discontinuity spacing decreases with higher weathering grades as expected. Three main discontinuity sets are formed and the spacings of the discontinuity sets formed in the thickly bedded sandstone reduced. The discontinuity development is related to weathering processes and governed by predefined, i.e., incipient or internal, planes of weakness that originate during early stages of rock formation and in response to the past and present three-dimensional stress field(s). The paper is motivated by the need to evaluate the engineering implications of mechanical discontinuity sets that are not apparent in rock at lower grades of weathering but that will be formed as a consequence of on-going weathering processes.
Computers & Geosciences, 64(2014), pp. 126–135, Mar 2014
In infrastructural projects, communication as well as information exchange and (re-)use in and be... more In infrastructural projects, communication as well as information exchange and (re-)use in and between involved parties is difficult. Mainly this is caused by a lack of information harmonisation. Various specialists are working together on the development of an infrastructural project and all use their own specific software and definitions for various information types. In addition, the lack of and/or differences in the use and definition of thematic semantic information regarding the various information types adds to the problem. Realistic 3D models describing and integrating parts of the earth already exist, but are generally neglecting the subsurface, and especially the aspects of geology and geo-technology. This paper summarises the research towards the extension of an existing integrated semantic information model to include surface as well as subsurface objects and in particular, subsurface geological and geotechnical objects. The major contributions of this research are the definition of geotechnical objects and the mechanism to link them with CityGML, GeoSciML and O&M standard models. The model is called 3D-GEM, short for 3D Geotechnical Extension Model.
Investigation of Remote Sensing for Potential Use in Dike Inspection
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 7(2), pp. 733-746, Feb 2014
Dikes are critical barriers against storm surges, sea level rise and flooding by rivers. Monitor... more Dikes are critical barriers against storm surges, sea level rise and flooding by rivers. Monitoring of these structures is most often done by visual inspection.This paper investigates remote sensing as a tool to facilitate the dike inspection process for grass-covered dikes. Two inspection criteria were considered,namely soil moisture and the
quality of the dike cover. Four types of remote sensing data were used, obtained in a ground-based campaign with hand-held sensors. These were thermal,visible,multi-spectral, and hyper-spectral remote sensing data. Relationships were found between the remote sensing data and the inspection criteria. In particular, afternoon thermal remote sensing data showed a negative correlation to soil moisture and broadband
multi-spectral remote sensing data, especially using the near-infrared band, showed a negative correlation to dike cover quality. Limitations for the use of thermal remote sensing are also discussed.
Engineering aspects and time effects of rapid deterioration of sandstone in the tropical environment of Sabah, Malaysia
Engineering Geology, 159(2013), pp. 20–30, Jun 12, 2013
Cut slopes in rock masses start to deteriorate directly after excavation due to stress relief and... more Cut slopes in rock masses start to deteriorate directly after excavation due to stress relief and weathering. The deterioration is a time dependent process that depends on the local climate and the rock mass including its history, and the environment. The amount of deterioration per time unit (�?the weathering intensity rate’) is not a constant over time, but is for most rock masses larger when the mass is less weathered and becomes smaller with further progressing weathering. A study has been carried out to establish the relationship between weathering intensity rate and exposure time for the intact rock strength (IRS) of sandstone in humid tropical areas. The data set for the study was collected in and near Kota Kinabalu, Sabah, Malaysia, which has a humid tropical climate. The geology in the area consists of thick sequences of sandstone and shale beds of the Crocker Formation. Results show that the best relationship between intact rock strength (IRS) and exposure time (t) is by a logarithmic function; IRS (t) = 105 �?� 34 log (1 + t). This relationship can likely be used for prediction of the intact rock strength development of similar sandstone over the engineering lifetime of man-made slopes in tropical areas.
Deterioration of rock masses in cut slopes is a main cause for slope failure along road corridors... more Deterioration of rock masses in cut slopes is a main cause for slope failure along road corridors. Deterioration is mainly due to stress relief and weathering. Deterioration rates depend on the properties of the rock mass including its history and the environment in which it is exposed. The rate decreases with time due to formation of a layer of residual material that prevents further contact between fresh mass and weathering agents. This research has been carried out to establish the relationship between weathering intensity rate and exposure time for the intact rock strength (IRS) of sandstone in the area around Kota Kinabalu (Sabah, Malaysia), which has a humid tropical climate. The geology in the area consists of interbedded thickly bedded sandstone and thinly laminated shale beds belonging to the Crocker Formation. The research shows that IRS is related to time following a logarithmic function: IRS (t)=105-34 log (1+t). This relationship is likely also valid in other tropical areas and thus can be used for prediction of the intact rock strength development of sandstone over the engineering lifetime of man-made slopes in tropical areas.
Earth Surface Processes and Landforms, 36 (13), pp. 1705-1714, 2011
Due to various decay processes associated with weathering, the stability of artificial slopes in ... more Due to various decay processes associated with weathering, the stability of artificial slopes in weak rocks may be affected well within their envisaged engineering lifetime. Conceptually, the decay following the initial stress release after excavation can be described as a process seeking equilibrium between weathering and erosion. The extent to which such an equilibrium is actually reached influences the outcome of the weathering�?erosion decay process as well as the effects that the decay has on the geotechnical properties of the exposed rock mass, and thus ultimately the stability of slopes affected by erosion and weathering. This paper combines two conceptual models for erosion and weathering, and derives a numerical model which predicts the resulting slope development. This can help to predict the development of a slope profile excavated in a weak rock in time, and can be extended with the addition of strength parameters to the weathering profile to enable prediction of slope stability as a function of time.
SCIENCE CHINA Technological Sciences, 54(1), pp. 210-220, 2011
The forecasting of the failure time of a slope remains a worldwide problem because of many differ... more The forecasting of the failure time of a slope remains a worldwide problem because of many different possibilities of geological conditions in combination with many varying external factors such as climate and vegetation, and not well-defined or unknown time effects in deformation and failure models. The aim of this paper is to suggest a new method to carry out the phase division and to explore tangential angular features of the displacement-time curve of creep slopes as well as the acceleration characteristics in the process of slope deformation and the pre-warning criteria for critical failure. An imminent failure is pro-ceeded with usually three basic deformation phases, namely primary creep (“decelerated”), secondary creep (“steadystate”) and tertiary creep (“accelerated”). Mostly, only during the accelerated phase the imminence of a possible slope failure is recognized. The analysis of displacement data from a series of landslides allowed to recognize different evolutionary patterns
of displacement. A quantitative approach was proposed to describe the tangential angle of the displacement-time curve and a new criterion based on the angle was put forward to divide the accelerated phase into three sub-phases: initial acceleration, medium acceleration, and the critical failure. A pre-warning criterion for critical failure is also proposed consequently. Changes of acceleration showed completely different characteristics from those of cumulative displacement and displacement in the process of slope deformation. The values of acceleration usually oscillate around 0 prior to the critical failure phase, whereas the acceleration increases abruptly when the deformation moves into the critical failure phase. This allows, therefore, for a method to forecast the time of the failure. So it is possible to define different alert acceleration threshold values to be used for emergency management.
Geomorphology, 114 (4), pp. 627-637., 2010
Landslide studies are commonly guided by ground knowledge and field measurements of rock strength... more Landslide studies are commonly guided by ground knowledge and field measurements of rock strength and slope failure criteria. With increasing sophistication of GIS-based statistical methods, however, landslide susceptibility studies benefit from the integration of data collected from various sources and methods at different scales. This study presents a logistic regression method for landslide susceptibility mapping and verifies the result by comparing it with the geotechnical-based slope stability probability classification (SSPC) methodology. The study was carried out in a landslide-prone national highway road section in the northern Himalayas, India. Logistic regression model performance was assessed by the receiver operator characteristics (ROC) curve, showing an area under the curve equal to 0.83. Field validation of the SSPC results showed a correspondence of 72% between the high and very high susceptibility classes with present landslide occurrences. A spatial comparison of the two susceptibility maps revealed the significance of the geotechnical-based SSPC method as 90% of the area classified as high and very high susceptible zones by the logistic regression method corresponds to the high and very high class in the SSPC method. On the other hand, only 34% of the area classified as high and very high by the SSPC method falls in the high and very high classes of the logistic regression method. The underestimation by the logistic regression method can be attributed to the generalisation made by the statistical methods, so that a number of slopes existing in critical equilibrium condition might not be classified as high or very high susceptible zones.
Transfer; Vakblad over internationalisering in het hoger onderwijs. 16 (9). pp. 22-23. (in Dutch), Jul 2009
(Interview with Hack) Wegenbouw leidt in het afgelegen Bhutan regelmatig tot verwoestende aardver... more (Interview with Hack) Wegenbouw leidt in het afgelegen Bhutan regelmatig tot verwoestende aardverschuivingen. Om daar een einde aan te maken, stond het ITC in Enschede het Himalayastaatje enkele jaren geleden bij met geologische expertise. Transfer ging kijken hoe de zaken er inmiddels voor staan.
Vi matrix. 15 (8). pp. 18-20. (in Dutch), 2008
“Gebrekkige communicatie was grootste veroorzaker faalkosten” was de kop boven een recent persber... more “Gebrekkige communicatie was grootste veroorzaker faalkosten” was de kop boven een recent persbericht over missers in de bouwsector. De “post” faalkosten wordt op een schrikbarende 6 miljard ingeschat: 10% van de bouwomzet, volgens USP Consultancy. Dit bureau onderzocht recent waar die kosten vooral uit bestonden. De bouwsector schrijft de oorzaak behalve aan te weinig aandacht voor uitvoerbaarheid in de omwerpfase (20%), voornamelijk toe aan een gebrekkige gegevensuitwisseling en communicatie (21%). Her bouwproces is wat betreft aantal partijen en deelprocessen immers bijzonder complex. Al deze min of meer losse partijen en processen moeten gecoördineerd en op elkaar afgestemd worden. Waar zich veel afstemmingsmomenten voordoen, is het risico op “falen” ook groot. De aandacht voor gegevensuitwisseling is dus essentieel en standaardisatie, technisch en semantisch, eerder eis dan wens. GIS/CAD-fabrikanten als Autodesk en Bentley richten hun software daarom in op verbetering van de onderlinge communicatie tijdens civiele projecten. Zodat iedereen over dezelfde informatie beschikt en er de status van kent. Het gaat niet alleen om “communicatie”, maar vooral ook om de kwaliteit van de gebruikte en uitgewisselde gegevens. Een voorbeeld is de zettingstrog van bijna een meter diep, die boven een doordruk persleiding van 1,9 meter diameter ontstond op de baan van de Rijswijkse Golfclub. De persleiding ligt ter plaatse meer dan 20 meter onder de grond en het is een volstrekt raadsel hoe dit kon gebeuren. Onnauwkeurige en incomplete gegevens van de ondergrond en/of een extreem slechte uitvoering van her werk door miscommunicatie ligt voor de hand.
The International Institute for Geo-Information Science and Earth Observation (ITC) and Witteveen... more The International Institute for Geo-Information Science and Earth Observation (ITC) and Witteveen + Bos Consultants have recently executed a feasibility study on upgrading the Beskyd railway tunnel in the Ukraine (Photo 1). This tunnel is located in the western region of the Ukraine, and forms part of the important railway line between East and West Europe (Figure 1). Four years ago, Ukrainian Railways received a loan from the European Bank for Reconstruction and Development (EBRD) to upgrade this railway connection. Obviously, little interest in East-West connections existed in the days of the Iron Curtain, but since the changes in the early 1990s economic cooperation between East and West has been booming and as a consequence traffic between East and West has also been increasing.
Engineering Geology; 91(1); pp. 4–15, 2007
Earthquakes are a major trigger for instability of natural and man-made slopes. Often the instabi... more Earthquakes are a major trigger for instability of natural and man-made slopes. Often the instability of slopes due to an
earthquake causes more destruction and kills more people than the actual earthquake itself. A comparison is made between different methodologies to analyze the potential stability of slopes during earthquakes. Theoretically, it seems simple to calculate the stability of a slope during an earthquake. In reality, however, the stability is influenced by so many parameters that are either not known or which influence is so poorly known that a decent estimation of stability cannot be made. Offshore the situation is worse because proper data required for stability calculations are even less available than onshore. On- and offshore, erosion and weathering create continuously slopes that may become unstable during a future earthquake, offshore also sedimentation creates
continuously new slopes. Another fundamental problem in stability analysis is the complicated and largely unknown behavior of seismic waves in three-dimensions in natural materials. The lack of accurate data and the unknown behavior of seismic waves in three-dimensions make estimations of slope stability during an earthquake unreliable.
Bulletin of Engineering Geology and the Environment, 65(2), pp 143-153, May 2006
Full three-dimensional modelling has been developed and is
implemented for many sites where engi... more Full three-dimensional modelling has been developed and is
implemented for many sites where engineering structures are built. Such computer models of the subsurface allow for a more sophisticated handling of subsurface data leading to, for example, better dimensioning of geotechnical units,
the evaluation of hazard and risk, foundation design, tunnel routing, planning and building, etc. Other applications are the back-analysis for completed civil engineering projects
to verify the correctness of assumed and estimated ground models and parameters, the verification of the correctness of constitutive models for ground behaviour and the use of back analysis to improve building methodologies or equipment. The
paper illustrates some of these advantages with a number of stateof- the-art applications of threedimensional modelling in engineering geology and geotechnical engineering,
highlighting a number of key issues when computer-aided 3D
modelling is used: the definition of geotechnical (homogeneous) zones, scale and detail, uncertainty and
likelihood of the developed model.
Environmental & Engineering Geoscience. 12 (1), pp. 39-51, 2006
Following the initial stress release after excavation of a road cut, weathering and erosion proce... more Following the initial stress release after excavation of a road cut, weathering and erosion processes will start acting on the newly exposed slope material. As field observations show, the resulting degradation may have significant effects well before the envisaged engineering lifetime of the slope ends. The data set obtained by 12 years of fieldwork by the International Institute for Geo-Information Science and Earth Observation and Delft University of Technology was used to assess and quantify the time-related degradation of rock masses by weathering. The results of a bootstrap analysis of the data show a close relationship between the weathering rates, the slope aspect, and the prevailing wind directions during rainfall events. For the study area around Falset it can be concluded that in shales, marls, and similar materials containing clays (especially swelling clays), weathering rates are highest in slopes facing the prevailing winds during rainfall because of more frequent and intense cyclic wetting and drying. The same holds true for more resistant materials such as limestones, which are interbedded with weak materials such as shales and marls. In soluble materials such as the gypsum unit investigated here, water retention in slopes sheltered from the winds facilitates chemical weathering, and it is in these lee-side slopes that the highest weathering rates are found. These relations can be used to predict weathering rates and, therefore, also weathering degree as a function of time. With the use of a probabilistic slope-stability assessment method, the time-related slope stability can also be predicted.
Uploads
Journal Papers by Robert H R G K Hack
quality of the dike cover. Four types of remote sensing data were used, obtained in a ground-based campaign with hand-held sensors. These were thermal,visible,multi-spectral, and hyper-spectral remote sensing data. Relationships were found between the remote sensing data and the inspection criteria. In particular, afternoon thermal remote sensing data showed a negative correlation to soil moisture and broadband
multi-spectral remote sensing data, especially using the near-infrared band, showed a negative correlation to dike cover quality. Limitations for the use of thermal remote sensing are also discussed.
of displacement. A quantitative approach was proposed to describe the tangential angle of the displacement-time curve and a new criterion based on the angle was put forward to divide the accelerated phase into three sub-phases: initial acceleration, medium acceleration, and the critical failure. A pre-warning criterion for critical failure is also proposed consequently. Changes of acceleration showed completely different characteristics from those of cumulative displacement and displacement in the process of slope deformation. The values of acceleration usually oscillate around 0 prior to the critical failure phase, whereas the acceleration increases abruptly when the deformation moves into the critical failure phase. This allows, therefore, for a method to forecast the time of the failure. So it is possible to define different alert acceleration threshold values to be used for emergency management.
earthquake causes more destruction and kills more people than the actual earthquake itself. A comparison is made between different methodologies to analyze the potential stability of slopes during earthquakes. Theoretically, it seems simple to calculate the stability of a slope during an earthquake. In reality, however, the stability is influenced by so many parameters that are either not known or which influence is so poorly known that a decent estimation of stability cannot be made. Offshore the situation is worse because proper data required for stability calculations are even less available than onshore. On- and offshore, erosion and weathering create continuously slopes that may become unstable during a future earthquake, offshore also sedimentation creates
continuously new slopes. Another fundamental problem in stability analysis is the complicated and largely unknown behavior of seismic waves in three-dimensions in natural materials. The lack of accurate data and the unknown behavior of seismic waves in three-dimensions make estimations of slope stability during an earthquake unreliable.
implemented for many sites where engineering structures are built. Such computer models of the subsurface allow for a more sophisticated handling of subsurface data leading to, for example, better dimensioning of geotechnical units,
the evaluation of hazard and risk, foundation design, tunnel routing, planning and building, etc. Other applications are the back-analysis for completed civil engineering projects
to verify the correctness of assumed and estimated ground models and parameters, the verification of the correctness of constitutive models for ground behaviour and the use of back analysis to improve building methodologies or equipment. The
paper illustrates some of these advantages with a number of stateof- the-art applications of threedimensional modelling in engineering geology and geotechnical engineering,
highlighting a number of key issues when computer-aided 3D
modelling is used: the definition of geotechnical (homogeneous) zones, scale and detail, uncertainty and
likelihood of the developed model.
quality of the dike cover. Four types of remote sensing data were used, obtained in a ground-based campaign with hand-held sensors. These were thermal,visible,multi-spectral, and hyper-spectral remote sensing data. Relationships were found between the remote sensing data and the inspection criteria. In particular, afternoon thermal remote sensing data showed a negative correlation to soil moisture and broadband
multi-spectral remote sensing data, especially using the near-infrared band, showed a negative correlation to dike cover quality. Limitations for the use of thermal remote sensing are also discussed.
of displacement. A quantitative approach was proposed to describe the tangential angle of the displacement-time curve and a new criterion based on the angle was put forward to divide the accelerated phase into three sub-phases: initial acceleration, medium acceleration, and the critical failure. A pre-warning criterion for critical failure is also proposed consequently. Changes of acceleration showed completely different characteristics from those of cumulative displacement and displacement in the process of slope deformation. The values of acceleration usually oscillate around 0 prior to the critical failure phase, whereas the acceleration increases abruptly when the deformation moves into the critical failure phase. This allows, therefore, for a method to forecast the time of the failure. So it is possible to define different alert acceleration threshold values to be used for emergency management.
earthquake causes more destruction and kills more people than the actual earthquake itself. A comparison is made between different methodologies to analyze the potential stability of slopes during earthquakes. Theoretically, it seems simple to calculate the stability of a slope during an earthquake. In reality, however, the stability is influenced by so many parameters that are either not known or which influence is so poorly known that a decent estimation of stability cannot be made. Offshore the situation is worse because proper data required for stability calculations are even less available than onshore. On- and offshore, erosion and weathering create continuously slopes that may become unstable during a future earthquake, offshore also sedimentation creates
continuously new slopes. Another fundamental problem in stability analysis is the complicated and largely unknown behavior of seismic waves in three-dimensions in natural materials. The lack of accurate data and the unknown behavior of seismic waves in three-dimensions make estimations of slope stability during an earthquake unreliable.
implemented for many sites where engineering structures are built. Such computer models of the subsurface allow for a more sophisticated handling of subsurface data leading to, for example, better dimensioning of geotechnical units,
the evaluation of hazard and risk, foundation design, tunnel routing, planning and building, etc. Other applications are the back-analysis for completed civil engineering projects
to verify the correctness of assumed and estimated ground models and parameters, the verification of the correctness of constitutive models for ground behaviour and the use of back analysis to improve building methodologies or equipment. The
paper illustrates some of these advantages with a number of stateof- the-art applications of threedimensional modelling in engineering geology and geotechnical engineering,
highlighting a number of key issues when computer-aided 3D
modelling is used: the definition of geotechnical (homogeneous) zones, scale and detail, uncertainty and
likelihood of the developed model.
De belangrijkste voorwaarde is dat de bodemdaling door de gaswinning samen met de zee-spiegelstijging binnen de toegestane gebruiksruimte blijft.1 De andere voorwaarde is dat de (dynamische) natuur in en rondom de Waddenzee2 niet wordt aangetast door bodemdaling als gevolg van de gaswinning. Mocht dit wel het geval zijn dan wordt de gaswinning beperkt of gestopt. Dit is het zogenaamde �?Hand aan de kraan’-principe. Om te bepalen of aan deze voorwaarden wordt voldaan, is in het Rijksprojectbesluit en de Natuurbeschermingswetver-gunningen (verder de Nb-wetvergunningen) bepaald dat de bodemdaling en de natuurwaar-den moeten worden gemonitord door de NAM. De NAM rapporteert jaarlijks over de monitoring aan de minister van Economische Zaken (EZ).
Nu ligt het Tussenrapport alternatievenafweging1 voor, dat als doel heeft onderscheidende alternatieven te beschrijven, zodat de minister kan kiezen welke alternatieven verder onder-zocht gaan worden. In dit advies spreekt de Commissie voor de milieueffectrapportage (hierna �?de Commissie’)2 zich uit over opzet en volledigheid van het Tussenrapport. Bij deze beoordeling heeft de Commissie ook het rapport van Deltares Toetsing Tussenrapport Heraf-weging verwerking productiewater Schoonebeek3 betrokken.
BV (NAM) de mogelijkheid om onder randvoorwaarden aardgas te produceren in het Waddenzeegebied uit de zes velden Moddergat, Nes, Lauwersoog C, Lauwersoog West, Lauwersoog
Oost en Vierhuizen Oost. De belangrijkste randvoorwaarde is dat de bodemdaling door de gaswinning samen met de
zeespiegelstijging niet meer mag zijn dan 5 of 6 mm/jaar.1 De andere randvoorwaarde is dat de (dynamische) natuur in en rondom de Waddenzee2 niet wordt aangetast door bodemdaling als gevolg van de gaswinning. Mocht dit wel het geval zijn dan wordt de gaswinning beperkt of gestopt. Dit is het zogenaamde “hand aan de kraan” principe. Om te bepalen of aan deze randvoorwaarden wordt voldaan, is in het Rijksprojectbesluit en de Natuurbeschermingswetvergunningen
(verder de Nb-wetvergunningen) bepaald dat de bodemdaling en de natuurwaarden moeten worden gemonitord door de NAM. De NAM rapporteert jaarlijks over de monitoring aan de minister van Economische Zaken (EZ).
opsporen en winnen van schaliegas (en steenkoolgas) in Nederland in termen van veiligheid voor natuur, mens en milieu. Met de aanvullende vraag op welke wijze de Nederlandse weten regelgeving de risico’s en gevolgen adresseert en mitigeert”. Op grond van dit onderzoek wil de Minister van EZ een besluit nemen over het al dan niet voortzetten van de procedures voor proefboringen naar schaliegas. De Minister van EZ heeft de Commissie voor de Milieueffectrapportage advies gevraagd over de kwaliteit van het onderzoek.
zeespiegelstijging niet meer mag zijn dan 5 of 6 mm/jaar.1 De andere randvoorwaarde is dat de (dynamische) natuur in en rondom de Waddenzee2 niet wordt aangetast door bodemdaling als gevolg van de gaswinning. Mocht dit wel het geval zijn dan wordt de gaswinning beperkt of gestopt. Dit is het zogenaamde “hand aan de kraan” principe. Om te bepalen of aan deze randvoorwaarden wordt voldaan, is in het Rijksprojectbesluit en de Natuurbeschermingswetvergunningen (verder de Nb-wetvergunningen) bepaald dat de bodemdaling en de natuurwaarden moeten worden gemonitord door de NAM. De NAM rapporteert jaarlijks over de monitoring aan de minister van Economische Zaken (EZ).
It also contributes to the ambitions of the International Year of Planet Earth (2007-2009) aiming at increasing awareness of the public and politicians to a safer, healthier and wealthier society on this planet, and more in particular to the �?Megacities’ theme of the International Year.
Viscosity is the resistance to gradual deformation of a medium under shear stress. The viscosity can be independent from (�?Newtonian’ or �?ideal-viscous’ media) or dependent on (�?Non-Newtonian’ media) the shear strain-rate and time. Temperature, and confining pressure may also be of influence. Gases, fluids and many ground materials behave viscous, and also �?hard’ rocks may (seem to) behave viscous over long timespans under high confining stress or temperature.
Weathering in most grounds is normally a fairly slow process taking long (geological) times to weather a large volume of ground, but it should be realized that small changes of very small quantities of material of a ground by weathering happening in a relatively short time span already may jeopardize an engineering construction. For example, the rock on both sides of a joint plane after excavation being exposed to a new environment may weather by a depth of tens of a millimeter in a couple of days, months, or years after excavation. Then the shear strength of the joint plane may be significantly reduced due to weathering of the asperities on the joint plane and forming a thin layer of low shear strength infill material (e.g., clay) in the joint. Such reduction in shear strength is often enough to allow sliding of a rock block where that would not have been the case along the unweathered joint plane.
Weathering also allows loss of structure of ground. The geotechnical quality of ground is to a certain extent due to a tight structure of particles and blocks of ground material. The tightness of the structure is reduced if weathering causes removal of part of the material or reduces the strength of particles or blocks. The reduction in tightness, among others, allows displacements in the ground, reduction of stresses in the ground, reduction of shear strength between particles and blocks, and hence the overall geotechnical quality of ground. Therefore, weathering and the change of geotechnical properties with time during the lifetime of an engineering construction have to be incorporated in the design of any construction on or below the Earth surface.
Weathering is often assumed to be restricted to the Earth surface, but active weathering may take place deep under the surface, for example, around faults with percolating groundwater down to thousands of meters deep, and at surface weathered material may have moved down into the Earth crust by tectonic and sedimentary processes. Moreover, weathered material may be a relic of weathering under a past climate or environment that has changed since long. Hence, any weathered material can be encountered anywhere at the surface or in the subsurface of the Earth.
solutions to resolve infrastructural problems in urban areas resulting from economic growth and increased urbanisation. These two developments have been responsible for a signifi cant increase in European underground infrastructure in the past three decades. An even more spectacular growth can be witnessed in China since 2000. In this paper the use of the subsurface is described against a geological and geotechnical
background. In addition, due attention is given to legislation related to underground development. Current legislation in EU countries and beyond is far from adequate to resolve legal issues concerning subsurface structures. In this paper legislation relevant to environmental aspects of subsurface infrastructural elements, and the apparent lack of proper legislative frameworks in this fi eld at national and supra-national (EU) levels, is highlighted. As most indicators point to a more intensive use of the subsurface over the next few decades, geological and legislative constraints will become more and more decisive factors in enabling its optimal use.
of a study that investigates remote sensing for evaluating the soil moisture as a means to investigate the quality of a peat dyke. Correlations were found between soil moisture and thermal remote sensing data. Remote sensing provides useful information for soil moisture evaluation for dyke inspection and may be useful for dyke quality inspection.
IRS (t)=105-34 log (1+t). This relationship is likely also valid in other tropical areas and thus can be used for prediction of the intact rock strength development of sandstone over the engineering lifetime of man-made slopes in tropical areas.