H.R.G.K. Hack

3D-GEM: Geo-technical extension towards an integrated 3D information model for infrastructural development

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. Innovative model (3D-DEM) for semantic and geometric properties of geo-technical data.First model to reflect needs of users involved in infrastructural projects.The model can be easily integrated with above surface data via CityGML.The models provide links to other geological models GeoSciML and O&M.

Sustainable development and management of the shallow subsurface.

This book is a compilation of topics and issues the authors think are required for a Sustainable Development and Management of the Subsurface. It attempts to arrive at a logic structure for dealing with the wide variety of aspects concerning the use of underground space, both time wise and geographically. The book aims to address engineers, teachers, (junior) scientists, and all others involved in subsurface construction providing an overview of not only technical aspects but also legal, governmental and policy making issues. It is a reference for the general public interested in the Earth science aspects of future cities and its citizens. 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.

Predicting Rock Mass Decay in Engineering Lifetimes: The Influence of Slope Aspect and Climate

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.

Geo-environmental aspects of European underground infrastructure

Underground excavation techniques have become safer, cheaper and faster. Governments of European countries and certain industrial sectors have shown to be prepared to make long-term investments in finding environmentally friendly solutions to resolve infrastructural problems in urban areas resulting from economic growth and increased urbanisation. These two developments have been responsible for a significant 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 field 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.

Seismic Slope Performance: Comparison of FEM Results to Displacement-Based Methods

Soil slopes from six types of generic soils (three sands and three clays) were modeled systematically as step-like slopes with the stress-deformation plane-strain finite element method (FEM). The models are assessed at different slope heights (5–20 m for the clay slopes and 5–40 m for the sand slopes), and monochromatic seismic loads with different frequencies (1, 2, 4, 6 Hz). At yield, the peak accelerations and slope displacements computed with the FEM are compared to the predictions from two displacement-based methods: Californian (Blake TF, Hollingsworth RA, Stewart JP (2002) Recommended procedures for implementation of DMG special publication 117: Guidelines for analyzing and mitigating landslide hazards in California. Southern California Earthquake Center, University of Southern California, California, 110p), and USGS Jibson (Eng Geol 91:209–18, 2007). For the slopes in clay, the results from the Californian method are in agreement with the FEM results for 4 and 6 Hz, while better matches between the FEM and the USGS method are obtained for 2, 4, and 6 Hz. The FEM results for the slopes in sand were compared to the Californian displacement-method only because this approach is calibrated with different types of materials and failure types while the USGS cannot be compared to these results as it is restricted to translational slip surfaces and the sands show more circular slip surfaces. The Californian predictions from the sand slopes are comparable, to the FEM results but with higher scatter. The FEM outputs provide further valuable insight among the relations from the different variables.

Potential of Using Remote Sensing Data for Dike Inspection

Dikes are increasingly becoming structures of major importance in view of sea level changes. Dike inspectors monitor dikes visually whilst walking the dike. It has been proposed that remote sensing could be used to make dike inspection faster and cheaper. This paper presents the results of a study which investigates remote sensing for evaluating the soil moisture and dike grass cover quality. Correlations were found between soil moisture and thermal and multispectral remote sensing data, and between dike grass cover quality and multispectral remote sensing data. Remote sensing provides useful information for soil moisture and grass cover quality evaluation for dike inspection and may be useful for dike quality inspection.