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In this paper the spatial structures of cone penetration test parameters in a liquefaction site in Taiwan are estimated based on multiple CPTs conducted in-situ. The study area was divided into three sub-regions based on the geological condition of the study area. The results show that in the vertical profile, cone tip resistance ( q c ) has a larger scale of fluctuation (SOF) than that of sleeve friction ( f s ). The soil profile which is composed of various sources and complex process of deposition has a smaller SOF in q c parameter. However, the spatial structure in f s parameter is not sensitive to the geological formation. The analysis results of the CPT data in horizontal direction indicate that the correlation distances of q c and f s in horizontal direction are similar. The horizontal spatial structure is dominated by the anisotropy of the geological and river systems. In conclusion, this study demonstrates that a proper geological zonation is necessary for estimating the spatial structure in both the vertical and horizontal directions.

Based on field investigation of the constituent structure and geological formation of the Maoping landslide, the authors made an in-depth study of the deformation characteristics and triggering mechanism of the reservoir-induced slide through comprehensive analysis of the about 13 years observation data. The Maoping landslide, the largest ancient landslide in Geheyan reservoir, with a volume of 23.5 million m3, is located on the left bank of the Qingjiang River, 66 km upstream of Geheyan dam. In April 1993 reservoir inundation reactivated the landslide, which resulted in relocation of a village of 290 people. Since then the landslide body has been experiencing persistent deformation with an observed maximum displacement of 2841.4 mm up to October 2005. Therefore, further development of deformation of the landslide becomes a great concern for the safety of the reservoir and dam. The analysis results show that the Maoping landslide is an ancient landslide that is an accumulation of several consequent slides along the bank slope and experienced several secondary slumps in its front in later stages. The ongoing deformation of the reactivated landslide is controlled by mechanical properties of materials and hydraulic effects induced by reservoir. The slip process is of creep deformation as a whole, and appears to be attenuating in later stage, which indicates very low possibility of the high-speed slip and integral failure of the slide.

For the disposal of high-level waste (HLW) in a deep geological formation as Boom Clay, safety assessment studies have shown that long lived 79Se is one of the more critical fission products. Therefore, the knowledge of its migration properties (diffusion, retention) through the geological barrier (Boom Clay) is of paramount importance. The migration behaviour of selenium strongly depends on its speciation. Under reducing conditions, selenide would be the dominant species and selenium migration would mainly be controlled by the low solubility of Se(−II)-bearing minerals. However Se species are often found in redox disequilibrium and more oxidized species might also coexist. Therefore, the study of selenate migration requires attention, as it might be the most mobile selenium species in the host rock. Electromigration experiments performed with a 75Se-labeled selenate in Boom Clay indicate a high mobility for this species. The apparent diffusion coefficient (Dapp) of selenate in Boom Clay is estimated from electromigration experiments performed under different electric fields. Using two independent approaches, the value of Dapp for selenate is shown to fall in the range from 1.7×10−11 to 6.2×10−11 m2 s−1. Moreover, no reduction of selenate in Boom Clay was observed.

For more than 20 years, the Boom Clay layer has been investigated as a potential host formation for the disposal of high-level (HLW) and medium-level radioactive waste (MLW). Experimental work regarding gas generation and migration associated with a hypothetical waste repository in the Boom Clay has been carried out in an integrated approach in several Belgian and European projects. This paper describes the resulting current understanding of these issues for the considered host formation. Hydrogen is generated by the anaerobic corrosion of the waste canisters. There is an experimental evidence that the presence of methane forming bacteria in the Boom Clay (and sulfate-reducing bacteria to a lesser extent) can reduce the gas source term, as the bacteria use four molecules of hydrogen in their metabolic reactions to form one molecule of methane. Numerical modelling indicates that if the gas generation rate in the disposal gallery becomes higher than the rate of the dissolved gas evacuation by diffusion (advection is negligible) into the host formation, the gas pressure increases. This gas pressure build-up may lead to contaminated water being expelled into the clay. Indeed, a gas phase could be formed and its pressure could exceed the local total stress, leading to a mechanical deformation of the rock and to the formation of a preferential pathway for the migration of gas and possibly contaminated water. To study the potential effects of the mechanical deformation of clay on radionuclide transport, a long-term in situ gas migration experiment through an artificially created pathway in the Boom Clay was carried out. The experiment was followed by a tritiated water injection test in order to detect any local change in the radionuclide transport properties of the host rock. Current results indicate that the geological formation possesses good macroscopic self-healing properties since the experimental results were in good agreement with calculations in which the permeability and the dispersion coefficient for the undisturbed clay was used.

Analyses of the responses of a dormitory building and a highway bridge on the University of Mississippi's main campus to simulated earthquake conditions are presented. Interaction between the facility structural models and subsurface geology models has been computed using the ABAQUS three-dimensional, nonlinear-dynamic, finite element code. Facility structural modeling has been supported by geological investigations including stratigraphic, boring, and shear-wave velocity measurements performed at a variety of sites on the campus. Seismic potential has been investigated through field studies of faulting in surrounding counties. Acceleration records for shaking the interaction models have been generated using a combination of recorded motions and ground motion models. Three earthquakes have been examined, one with an epicenter at Charleston, MS, and the other two at Marked Tree, AR. Characteristic events of light, moderate, and severe intensities, with nominal moment magnitudes of 5.0, 6.5, and 8.0, respectively, have been simulated, enabling a vulnerability assessment over a range of likely facility response. A contour map of fundamental periods of the subsurface geology has been constructed from surface motions calculated using the weshake 5 program which accounts for propagation through the soil column. Such a map provides a quick guide to the tendency for interaction with facility structures at any site on campus. Eigenvalue and time history analyses of the facility structural/subsurface geology interaction models provide insight into the influence the subsurface geology has on the response behavior and damage that occurs in the facility structures.

The 1989 Loma Prieta, California earthquake (moment magnitude, M=6.9) generated landslides throughout an area of about 15,000 km2 in central California. Most of these landslides occurred in an area of about 2000 km2 in the mountainous terrain around the epicenter, where they were mapped during field investigations immediately following the earthquake. The distribution of these landslides is investigated statistically, using regression and one-way analysis of variance (ANOVA) techniques to determine how the occurrence of landslides correlates with distance from the earthquake source, slope steepness, and rock type. The landslide concentration (defined as the number of landslide sources per unit area) has a strong inverse correlation with distance from the earthquake source and a strong positive correlation with slope steepness. The landslide concentration differs substantially among the various geologic units in the area. The differences correlate to some degree with differences in lithology and degree of induration, but this correlation is less clear, suggesting a more complex relationship between landslide occurrence and rock properties.

One of the most significant effects of the 17 January, 1994 Northridge, California earthquake (M=6.7) was the triggering of thousands of landslides over a broad area. Some of these landslides damaged and destroyed homes and other structures, blocked roads, disrupted pipelines, and caused other serious damage. Analysis of the distribution and characteristics of these landslides is important in understanding what areas may be susceptible to landsliding in future earthquakes. We analyzed the frequency, distribution, and geometries of triggered landslides in the Santa Susana 7.5′ quadrangle, an area of intense seismic landslide activity near the earthquake epicenter. Landslides occurred primarily in young (Late Miocene through Pleistocene) uncemented or very weakly cemented sediment that has been repeatedly folded, faulted, and uplifted in the past 1.5 million years. The most common types of landslide triggered by the earthquake were highly disrupted, shallow falls and slides of rock and debris. Far less numerous were deeper, more coherent slumps and block slides, primarily occurring in more cohesive or competent materials. The landslides in the Santa Susana quadrangle were divided into two samples: single landslides (1502) and landslide complexes (60), which involved multiple coalescing failures of surficial material. We described landslide morphologies by computing simple morphometric parameters (area, length, width, aspect ratio, slope angle). To quantify and rank the relative susceptibility of each geologic unit to seismic landsliding, we calculated two indices: (1) the susceptibility index, which is the ratio (given as a percentage) of the area covered by landslide sources within a geologic unit to the total outcrop area of that unit; and (2) the frequency index [given in landslides per square kilometer (ls/km2)], which is the total number of landslides within each geologic unit divided by the outcrop area of that unit. Susceptibility categories include very high (>2.5% landslide area or >30 ls/km2), high (1.0–2.5% landslide area or 10–30 ls/km2), moderate (0.5–1.0% landslide area or 3–10 ls/km2), and low (

The natural gamma log is widely used in both cased and uncased boreholes to identify changes in lithology down the length of a borehole. This is particularly important in the ground investigation process where 100% core recovery is often not achieved in the borehole programme. In this paper the use of the gamma log to provide additional information from the ground investigation boreholes is examined and illustrated by a number of case histories. It is shown that the gamma log can be used to study both the lithological variations within an individual borehole and changes in geological structure across a construction site. It is also demonstrated that a geological formation or sequence can be classified in terms of its natural gamma signature, which enables the geologist to observe its presence over large distances on a regional basis. The importance of the calibration of the gamma sonde and the use of the correct logging speed is emphasised in the paper. The successful calibration of the log against a quarry wall using a known observed geological structure as a reference is also described together with the use of the resulting information to obtain a geological log for boreholes drilled behind the quarry face. Its use in extrapolating between boreholes to detect and trace the presence of a particular geological formation to estimate its vertical and lateral extent for possible extraction is also discussed.

Factors affecting the increase in weathering-rind thickness, i.e. weathering rates, were investigated using andesite gravel in fluvial terrace deposits with a known emergence time. The time between the age of each terrace formation (20, 130, 290 and 660 ka) and the present was assumed to be the weathering period. Three zones were classified from measurements of the Vickers hardness number (VHN) across weathering rinds from the rock surface to the inner fresh part: (1) Zone I, the outermost brown layer, which has low VHN values of 10 to 80 gf/μm2; (2) Zone II, the inner gray layer which has increasing VHN values (100 to 500 gf/μm2) with increasing depth; (3) the innermost fresh part, which has large VHN values of 500 gf/μm2. In this paper, Zones I and I+II are defined as the brown layer and the weathering rind, respectively. Diffusion theory was applied to the relationship, between the thickness of the brown layer or the weathering rind and time (weathering periods). The results show that the thickness of the brown layer depends mainly on time, whereas the thickness of the weathering rind is controlled by the porosity of the host rock as well as time. Consequently, rocks with higher porosity have thicker weathering rinds than brown layers.

From March 1994 to August 1996, ANDRA conducted a large reconnaissance work on three sites for possible underground research laboratories. These surveys highlighted for each site the presence of a geological formation, the properties of which meet the requirements of the French Fundamental Safety Rules. On the East site, the selected formation is a 130 m thick argillite layer. On the Gard site the layer is composed of close-packed siltites which are 200–400 m thick. On the Vienne site a hercynian granodiorite batholith was found under a 160 m thick jurassic overdurden.

The deep, unconsolidated sedimentary aquifers of eastern China are heavily over-exploited and this causes aquifer compaction 1 which results in land subsidence. The geological formation contains significant thicknesses of clay which introduces time delays between the extraction of the groundwater and the resulting subsidence. A new computer code called the Interbed Drainage Package has been developed for the popular MODFLOW model to address this behaviour. It has been applied in a simulation of the port of Hangu and the results are being used to manage the land subsidence problem.

A detailed geological investigation was conducted along the section of highway between Station 00 and Station 88 km of the proposed Aqaba to Ras El Naqab highway in Jordan including the Ras El Naqab Escarpment (Station 75–80 km). The Escarpment area is characterized by soil-rock slope failures, and a complex geological pattern of rock units and faults in a rugged terrain. The geological sequence along the highway alignment consists initially of the Kurnub Sandstones Group and mainly within the Upper and Lower Ajlun Formations. The mechanics of movements associated with the Kurnub Sandstone Group include erosion and toppling of sandstone blocks where undercut. Movements manifested within the Upper Ajlun Formation are due to the opening of joints, formation of gulls, cambering, toppling, sliding, rockfalls and the dislocation of limestone blocks. These slope failures associated with the Lower Ajlun Formation are relatively small while large-scale movements and slips occur within the marl and clay. After extensive slope stability analyses were performed an alignment for the proposed road, including the Escarpment stretch was selected, that also included any special construction considerations. Three locations were selected for the detailed slope stability analyses; initially the critical soil parameters were determined assuming that the slopes are marginally stable. Alternate measures for the stability were then considered and the relative effects on the safety factor were analyzed to determine optimum solutions for locating the proposed road. The recommended alignment is situated adjacent to the existing road and located on the west up to Station 75 + 000 km and from Station 76 + 000 km to Station 79 + 700 km. Between Station 75 + 000 km and Station 79 + 700 km to the crest of the Escarpment the new alignment is located east of the existing road. Design criteria adopted for slopes constructed within the Upper Ajlun Formation include protection of exposed marl and clay slopes, sealing of open joints and fractures within the limestone and minimizing the surface areas of marls and clays in slope faces. Criteria for design of slopes within the Lower Ajlun include those presented for the Upper Ajlun as well as proper design of slope angles, placement of interceptor drains, and specific construction techniques to be adopted where mantle creep is anticipated. Features associated with the Kurnub Sandstones require the installation of surface drainage measures as well as revetment techniques to prevent encroachment of rock-block falls onto the highway or into drainage channels.

The geological formation known as the "Terres Noires" covers large areas of southeastern France, between the Rhône valley and the pre-Alpine hills. This formation consists mainly of dark marls of the basal Upper Jurassic. These marls are very susceptible to weathering and are particularly prone to erosion, resulting in high solid tranport. This paper attempts to quantify this transport in experimental catchment areas, and shows that a forest cover can play a major role in preventing this type of phenomenon. Weathering of this formation may also lead to gravity instabilities in fresh marl (althought this is rare) and , much more frequently, in the surficial weathered material., La formation géologique appelée "Terres Noires" couvre de larges zones du Sud Est de la France entre la vallée du Rhône et les collines des Préalpes.Elle consiste principalement en marnes sombres de Jurassique Supérieur. Ces marnes sont très sensibles à la météorisation et sont particulièrement sujettes à l'érosion, ce qui fournit un transport solide très important. Cet article quantifie ce transport solide à partir de mesures faites dans des bassins versants expérimentaux et montre le rôle que joue la forêt dans la réduction de ces phénomènes. L'évolution au cours du temps de cette formation conduit aussi, mais rarement, à des instabilités gravitaires de la marne en place, et beaucoup plus fréquemment à des mouvements du matériau altéré de surface.