Abstract Metastable soils may collapse because of the nature of their fabric. Generally speaking, these soils have porous textures, high void ratios and low densities. They have high apparent strengths at their natural moisture content, but large reductions of void ratio take place upon wetting and, particularly, when they are loaded because bonds between grains break down upon saturation. Worldwide, there is a range of natural soils that are metastable and can collapse, including loess, residual soils derived from the weathering of acid igneous rocks and from volcanic ashes and lavas, rapidly deposited and then desiccated debris flow materials such as some alluvial fans; for example, in semi-arid basins, colluvium from some semi-arid areas and cemented, high salt content soils such as some sabkhas. In addition, some artificial non-engineered fills can also collapse. In the UK, the main type of collapsible soil is loess, though collapsible non-engineered fills also exist. Loess in the UK can be identified from geological maps, but care is needed because it is usually mapped as ‘brickearth’. This is an inappropriate term and it is suggested here that it should be replaced, where the soils consist of loess, by the term ‘loessic brickearth’. Loessic brickearth in the UK is found mainly in the south east, south and south west of England, where thicknesses greater than 1 m are found. Elsewhere, thicknesses are usually less than 1 m and, consequently, of limited engineering significance. There are four steps in dealing with the potential risks to engineering posed by collapsible soils: (1) identification of the presence of a potentially collapsible soil using geological and geomorphological information; (2) classification of the degree of collapsibility, including the use of indirect correlations; (3) quantification of the degree of collapsibility using laboratory and/or in situ testing; (4) improvement of the collapsible soil using a number of engineering options.

Abstract In engineering terms, all materials deposited as a result of glacial and periglacial processes are transported soils. Many of these deposits have engineering characteristics that differ from those of water-lain sediments. In the UK, the most extensive glacial and periglacial deposits are tills. Previously, engineering geologists have classified them geotechnically as lodgement, melt-out, flow and deformation tills, or as variants of these. However, in this book tills have been reclassified as: subglacial traction till, glaciotectonite and supraglacial mass-flow diamicton/glaciogenic debris-flow deposits (see Chapter 4 , Sections 4.1 – 4.3 ). Because this classification is new, it is not possible to relate geotechnical properties and characteristics to the subdivisions of the new classification. Consequently, the domain/stratigraphic classification, recently developed by the British Geological Survey and others, has been used and their geotechnical properties and characteristics are discussed on this basis. The geotechnical properties and characteristics of the other main glacial and periglacial deposits are also discussed. For some of these (e.g. glaciolacustrine deposits, quick clays and loess), geohazards relating to the lithology and/or fabric of the deposit are discussed along with their properties. Other geohazards that do not relate to lithology and/or fabric are discussed separately as either local or regional geohazards. In some cases (e.g. glaciofluvial sands and gravels), the geotechnical properties and behaviour are similar to sediments deposited under different climatic conditions; these deposits are therefore not discussed at length. Similarly, some of the local geohazards that are found associated with glacial and periglacial deposits relate to current climatic conditions and are not discussed here. Examples include land-sliding and highly compressible organic soils (peats).

Abstract Over half of the world’s population now live in cities. In 2011 it was estimated that the global population exceeded 7 billion. Pressures on the environment including land use are increasing. The ground beneath cities and the interaction between physical, biological and chemical processes provides natural capital on which society depends. These benefits and the ground properties and processes that support and deliver them can be considered ecosystem services. Characterizing the ground properties on which ecosystem services depend involves a qualitative assessment of positive and negative impacts of proposed urban sustainability solutions, including use of the ground. The sustainability of a proposed solution depends on how the future might unfold. Future scenario analysis allows consideration of the social, technological, economic, environmental and political changes that may determine the ability of a proposed solution to deliver its benefits now and in the future. Analysis of the positive and negative impacts of a proposed use of the ground on ecosystem function, measured against future scenarios of change, can be integrated to deliver strategies for the future management of the ground and the wider environment beneath cities.

Abstract Over half of the world’s population is urbanized. Urban planners aim at sustainable development but often take more account of social and economic information than geoscience. Many authorities do not employ geoscientists. This leads to poor policies and decisions and increased costs and risks. Planning systems are complicated and lengthy, involving many participants from planners to elected members as well as the public who may have limited understanding of the importance of geoscience information, scientific methods and uncertainties in results. Careful presentation focusing on the requirements of each audience is needed. Researchers should engage with stakeholders to develop trust and understanding. Planners should be included in research teams. Information on resources, hazards and emissions should be combined with social and economic material. Collaboration with other specialists is important. Work is not over when the results are written up. Thorough dissemination is required for results to be used fully and properly. It is wise to train geoscientists in writing for, and communicating with, the public and media. Ongoing advice and guidance is needed not least when plans are reviewed and updated but that is often prevented by funding mechanisms.

Abstract Carboniferous deposits in Moscow are composed of interlaying carbonate and clay-marl massifs. The roof of Carboniferous deposits occurs at a depth 5–150 m below the surface. It has been affected by several generations of river erosion. Carbonate layers consist mainly of limestones karstified to a different extent. Suffosion development in overlaying sandy-clayey and sandy horizons resulting in karst-suffosion sinkholes and surface subsidence are related to the ancient buried karst forms. The geological map of Carboniferous deposits is compiled to a scale of 1: 10 000 for the entire territory of Moscow. The map shows the geological structure at the roof of Carboniferous deposits. It also displays the spatial distribution of various stratigraphical and lithological series of Carboniferous system, the subcrop topography of the Carboniferous deposits and thalwegs of pre-Jurassic and pre-Pleistocene (pre-glacial) buried river valleys and gullies. The specifics of karst development in Carboniferous limestone massifs are studied. Karstification and fracturing distribution is analysed in connection with the ancient topography. The geological map of Carboniferous deposits is one of the principal maps for compiling the map of karst and karst-suffosion hazard and the map of engineering geological zoning of Moscow.

Abstract One of the principle strategies of the European Community is efficient and sustainable usage of aggregate resources. The appropriation and implementation of these strategies are highly important. Rapid reductions in the usable aggregate resources, the possibility of future closure of quarries near the city centre and inefficient use of the resources are major problems for İstanbul. To provide efficient use of aggregate resources in İstanbul and its vicinity, it is therefore necessary to review the regional plan and develop new strategies for sustainable management of resources. However, sustainability is affected by local factors such as availability of a suitable transportation infrastructure and a lack of detailed knowledge of the geology. It is therefore important to manage existing resources effectively, and maximize the resources through use of operational systems that maintain quality.

Abstract Desk study is an essential part of all civil engineering project ground investigations. It is usually a collation and review of existing data and information about a site and, in some cases, the surrounding area, and carried out at an early stage of the ground investigation to inform and guide the ground investigation. It should provide suitable data and information to assess the ground conditions and the implications for the proposed engineering design. A similar approach can be taken to inform local, regional or national government with regard to development and the redevelopment of urban areas where ground investigation data and information are available. This paper describes a spatially defined geotechnical information system (GIS) designed to provide geological, geotechnical and geoenvironmental data and information for Glasgow City Council (Scotland). The system contains three main parts: the geology (bedrock, Quaternary and artificial deposits and the thickness and depth of these deposits); the data are presented as various summary graphs illustrating the variation of various parameters as well as a geotechnical and geoenvironmental database; and tools specifically developed to present the data. As undermining is a hazard in part of Glasgow, a dataset showing the distribution of mining is included. Further interpretation of the characteristics of the geological units has produced an engineering geological classification which may be used to provide rapid assessment of the engineering geological conditions.

Abstract Cenozoic age detrital sequences in the Pilbara region of Western Australia are becoming a focus for engineering geological and hydrogeological investigations with an increasing number of final open-pit walls developed in these materials for iron ore mining. Historically, detrital sequences were classified chronostratigraphically. However, within each chronostratigraphic unit exist sub-units of variable engineering geological and hydrogeological character. As the majority of drill-hole data from Pilbara iron ore mines is derived from reverse circulation techniques, a methodology to identify the engineering geological units through downhole geophysics and geochemical assays was required to progress model development to the level of detail required for geotechnical and hydrogeological studies. The methodology entails a review of cored hole data and use of twin holes to assess the typical geochemical and geophysical signatures of units identified. Improved interpretation of reverse circulation drill-holes has resulted in the development of detailed 3D engineering geological models, which have improved the understanding of geological variability and engineering properties for geotechnical and hydrogeological studies.

Abstract Successful open-pit slope design depends on the formulation of a representative geotechnical model. This paper presents the development of an engineering geological rock-mass model as part of a feasibility geotechnical study for the Tampakan copper/gold open-pit mine in the Philippines. This porphyry deposit has been subjected to several cycles of volcanism, chemical alteration and tectonic disturbance resulting in a complex, highly fractured and brecciated rock mass. The model requirements for design were identified early in the project and a unique geotechnical logging system was developed to effectively capture the relevant rock-mass characteristics.

Abstract Surface mining of coal can involve extensive footwall slopes parallel to shallow to moderately dipping coal measures strata. Footwall failure mechanisms typically invoke bedding-parallel defects but also require either the existence of flatter structures, which cross-cut bedding, or require break-out through the rock mass to allow failure surfaces to emerge. Permian-aged Baralaba Coal Measures of the Bowen Basin, Queensland, are prospective for coal with extraction by open-pit methods. The Baralaba Coal Measures contains multiple seams within an interburden sequence comprising sandstone, siltstone, mudstone and carbonaceous variations. The coal measures sequence has been deformed into a complex pattern of NW-striking folds which has resulted in bedding dip ranging from 15° to 60°. Bedding has been classified as shallow (10–30°) to moderate (30–60°). Geotechnical investigations conducted to support coal extraction up to depths of 200 m suggest that structural controls strongly influence footwall slope design. For the purpose of footwall slope design, a distinction can be made between deposit areas of relatively simple structure (uniformly dipping bedding on fold limbs) and structurally complex areas (where layer-parallel shortening close to fold hinges has resulted in a system of low-angle thrusts and asymmetrical minor folds).

Abstract The Northern Wedge Failure (NWF) is a complex failure mass within Whitehall Quarry, Cambridge, New Zealand. Initiation of failure of the c. 500 000 m 3 mass occurred during spring of 1988. Complete failure was expected following displacement recordings of 2.3–5.6 m a −1 ; however, this did not eventuate. By the mid 1990s, the failure mass was deemed stable. In 2010, an engineering geological investigation was conducted to assess the stability of the NWF at that time. The rock mass that failed comprises moderately dipping interbedded feldspathic sandstone and argillaceous mudstone below a thin alluvial cover. It is bound by two fault planes, both exhibiting up to 100 mm of gravelly clay fault gouge. X-ray diffraction analysis of the gouge indicated the presence of kaolinite and montmorillonite, and Atterberg Limit tests showed the plastic and liquid limits to be 31% and 51%, respectively. Electronic distance monitoring (EDM) was carried out over 12 months. Recorded velocities increased by 17% above the 21 mm/month baseline over the wetter months. Limit equilibrium analysis carried out using historic and recent field and laboratory observations input to the computer software SWedge estimated a Factor of Safety (FOS) of 0.97. Complete failure of the NWF could be initiated at any time by an extended period of heavy rainfall and/or unloading of the toe or the stripping of overburden.

Abstract A landmark Australian landslide research project, that will produce a series of medium-scale landslide inventory and susceptibility zoning datasets for substantial areas of Australia, is proposed. The project will produce a series of planning tools to facilitate the implementation of the AGS 2007 Landslide Risk Management (LRM) guidelines within government, and also address the new paradigm in risk management of due diligence. The project will also summarize the current variable status of landslide regulations around the country at both state and local government levels. This project will complement the earlier National Disaster Mitigation funding of the Australian Geomechanics Society and will address the difficulty in assembling a meaningful landslide inventory, essential for the development of susceptibility and hazard maps in landslide risk management practice. Susceptibility maps are seen as the best product from which to produce planning and development control areas for use in local government planning schemes addressing landslide issues. The development of a National Landslide Inventory framework would enhance data collection standards for this hazard across Australia. The costs associated with landslide damage and management are poorly documented within Australia and this project will also contribute to enhancing this element. Preliminary figures from early work in this area suggests government spending in the Wollongong area alone is at least $5 million annually since 1950 on landslide related costs. The project will also result in a series of regional to local zoning inventory and susceptibility zoning datasets and associated maps ranging from 1:250 000 and perhaps in some areas up to 1:25 000 scales for substantial areas of Australia. A modelling process will also be documented to promote transparency and to facilitate subsequent review and revisions. Achieving appropriate levels of funding to undertake this project remains a priority for the team. However, substantial elements are being developed already (some of which are summarized in this paper) and the authors are confident this project will come to fruition.

Abstract Hong Kong has made considerable progress in reducing landslide hazards from man-made slopes. As a consequence, Hong Kong has recently commenced the systematic evaluation of landslides from natural slopes. This paper discusses the assessment approached adopted, limitations with the approach and the problems with landslide hazard assessment in general by means of a case study. The paper concludes that the current approach, whilst suitable for its original purpose, that is the rapid evaluation of the likely magnitude of landslide hazards at the review stage of a development, has limitations when used for systematic landslide assessments at existing developments. It is suggested that landslide hazard assessments to quantify ‘top events’, for example loss of life, would be an improved approach which would allow simplified quantitative risk assessment (QRA) to be undertaken. However, such an approach requires a significant level of engineering geological and engineering geomorphological input. In particular, the careful derivation of appropriate values of landslide magnitude and frequency, based on expert judgment and making use of available data, knowledge and experience.

Abstract In this article a method developed for the creation of a site classification map at a territorial scale, starting from the geological mapping available at 1:100 000 scale, is described. This map has been used to embed amplification factors as provided by the Italian seismic code in seismic hazard studies, in order to consider the contribution of the surface geology on the expected ground motion values. The Italian territory has been divided into polygons classified on the basis of lithologies that the seismic code considers homogeneous in their average seismic response. The data processing has been conducted in a GIS environment, starting from the digital format of the lithological map of Italy at 1:100 000 scale. Our results can be used in seismic risk analyses that take into account the local seismic amplification due to the geological characteristics of an area, and in studies on ground motion prediction equations (GMPE).

Abstract Ground models should be a fundamental outcome from all site investigations for civil engineering development and planning projects. Without them, it is not possible to: define the ground conditions; identify any geohazards or other engineering constraints; identify potential resources; provide a basis for construction tendering; establish risk registers; determine reference conditions; design the works; or evaluate the environmental consequences of projects. A methodology for ground model development has yet to be fully established, but understanding geomorphological processes and landforms is central to the creation of effective models. Therefore, it is necessary to develop a methodology that ensures geomorphology is fully integrated into the already well-defined approaches for investigating and interpreting the geological and geotechnical conditions. This happens most effectively where geomorphology is seen as part of engineering geology and is fully integrated in the site investigation process. This is not a universal situation however, as a great deal of geomorphological research is undertaken as part of physical geography and is not widely accessed during standard desk studies. Engineering geologists need to access this high-quality research and bring it into ground models that are presently biased towards geology and geotechnics. When this is achieved, engineering geological ground models will become genuinely fit for purpose.

Abstract Afulilo Dam was built as part of a hydroelectric scheme to augment the power supply for the island of Upolu, Samoa. The 23 m high concrete gravity dam sits on the crest of a waterfall that once drained an intermontane basin. Initially, concerns were expressed about a possible active fault through the dam site linked with a larger fault across the island. This assertion was refuted but not tested by the owners, and the dam came into operation as planned. This issue was again reviewed in 2009–10 as part of an environmental and power augmentation study. The opportunity was also taken to test the compliance of the dam with accepted international practices. Additional regional geological assessments, a review of the seismic data and further drilling at the dam site provided data to improve the geological model for the dam site. It is concluded and confirmed that there is no clear evidence for the existence of such faults. If they do exist, they are not active and therefore not significant for the safety of the dam.

Abstract The development of reliable subsoil models is one of the key points for the assessment of the seismic performance of existing strategic infrastructures, especially in many European countries where the seismic hazard varies from moderate to high. The strategic infrastructures are structures and components which have a crucial role in the social and economic development of a modern country, and include lifelines and industrial plants. Lifelines frequently have a linear development and can be affected by very heterogeneous and complex geological setting. Industrial plants, on the other hand, frequently treat toxic and flammable materials. This paper deals with the definition of an effective geological and geotechnical three-dimensional model of the Biferno River coastal plain in the Molise region (Italy) as a key for a quantitative assessment of real performances of strategic infrastructures. Some remarks on the site seismic vulnerability and on the regional and local geological, geomorphological and hydrogeological conditions are given. The key objective of the seismic vulnerability assessment is discussed in relation to the spatial variability of the geological and geotechnical characteristics.

Abstract In June 1992, five large rock caverns were unearthed in a village near Longyou County in Zhejiang Province, south China. The caverns were manually excavated about 2000 years ago in argillaceous siltstone of Cretaceous age. Faults are not well developed, however there are clay interlayers within argillaceous siltstone bedding at each cavern. Field investigations suggest that the ancients had realized the influence of the clay interlayers on the stability of caverns and altered their location and layout accordingly. Several preserved trial adits at the site are good evidence of this conclusion. These adits are apparently abandoned due to the presence of clay interlayers. This is probably the earliest known use of geological exploration by adit methods, an approach now widely used. In this paper, the engineering geological conditions, especially the development of the clay interlayers, are presented in some detail. Statistical analysis shows that the numbers and average thickness of clay interlayers in the five completed caverns are less than those in other outcrops. It is concluded that trial adit methods and experience by geological observation were adopted by the ancients 2000 years ago in the excavation of underground rock caverns.