bluuebunny/crossref_metadata_2025 huggingface dataset:
Laser-induced breakdown spectroscopy (LIBS) – an emerging field-portable sensor technology for real-time,

in-situ

geochemical and environmental analysis
Authors: Harmon Russell. S. , De Lucia Frank C. , Miziolek Andrzej W. , McNesby Kevin L. , Walters Roy A. , French Patrick D.
Published: November 2007

Laser-induced breakdown spectroscopy (LIBS) is a simple spark spectrochemical sensor technology in which a laser beam is directed at a sample to create a high-temperature microplasma. A spectrometer/array detector is used to disperse the light emission and detect its intensity at specific wavelengths. LIBS has many attributes that make it an attractive tool for chemical analysis. A recent breakthrough in component development, the commercial launching of a small, high-resolution spectrometer, has greatly expanded the utility of LIBS and resulted in a new potential for field-portable broadband LIBS because the technique is now sensitive simultaneously to all chemical elements due to detector response in the 200 to 980 nm range with 0.1 nm spectral resolution. Other attributes include: (a) small size and weight; (b) technologically mature, inherently rugged, and affordable components; (c)
in-situ
analysis with no sample preparation required; (d) inherent high sensitivity; (e) real-time response; and (f) point sensing or standoff detection. LIBS sensor systems can be used to detect and analyse target samples by identifying all constituent elements and by determining either their relative or absolute abundances.
Baseline geochemical survey of the Riverina region of New South Wales and Victoria, Australia: concentrations and distributions of As, Ba, Br, Cd, Co, Cr, F, Ga, Mo, Sb, U and V compared to national and international guidelines
Authors: Lech M.E. , de Caritat P.
Published: November 2007

This study discusses element excesses and deficiencies in the regolith of the Riverina region, which may impact on plant, animal and human health. Top (0–10 cm depth) and bottom (
c
. 60–90 cm depth) overbank sediment samples were collected near the outlets of 142 catchments and the composition of the <180 μm fractions determined. Total concentrations of As (0.8–159.8 mg/kg), Ba (189– 1263 mg/kg), Br (<1–89.5 mg/kg), Cd (<0.1–2.33 mg/kg), Cr (29–200 mg/kg), F (150–610 mg/kg), Ga (6.3–26.1 mg/kg), Sb (0.37–10.8 mg/kg), U (1.26– 8.49 mg/kg) and V (31–145 mg/kg) are locally elevated above national and international guidelines and these elements therefore have potential for health concerns. Concentrations in at least half of the samples are above the guidelines for Ba, Cr, F, Ga and V. Based on total concentrations, most elements are unlikely to cause harm due to their low plant uptake and/or strong adsorption onto soil particles; however, Cd, V and U in particular require further investigation. Total concentrations of Co (2.96–34.2 mg/kg) and Mo (0.5–1.9 mg/kg) are potentially deficient in parts of the region and can be remedied with the application of appropriate fertilizers.
3-D visualization as an aid to the hydrogeological conceptualization of the central South Downs
Authors: Robins N.S. , Dumpleton S. , Packman M.J.
Published: November 2007

Conceptual models are an essential part of groundwater investigations. The conceptualization process has lacked formality in the past, and has depended on the development of a set of 2-D cross-sections to portray a 3-D picture of groundwater flow as a means of bringing together the numerous and diverse relevant data sets. A more structured approach to developing the hydrogeological framework for the conceptual model is advocated using a 3-D visualization package to assemble the data, and working in three dimensions from the outset. The new method is tested on the complex central part of the English South Downs Chalk aquifer. Although the data needs areintensive, the model is extremely valuable in realisinga number of facets of groundwater flow previouslyunidentified. Other key advantages are that the 3-D model is flexible and can be amended from time to time without the need to start afresh, and that it provides a data platform and a means of further analysis bothin itself and in hydrogeological software such asMODFLOW.
Design Charts for 2D Consolidation under Time-Dependent Embankment loading
Authors: Razouki Sabah S. , Al-Zayadi Abbas A.
Published: November 2007

Design charts for the rate of settlement ofembankments on soft foundations aredeveloped on the basis of 2D consolidation during the construction and post-construction periods. The embankment loading is assumed toincrease linearly with time during construction and to remain constant thereafter.

The clay deposit is considered to consist of ahomogeneous layer of finite thickness and infinite lateral extent having cross-anisotropic permeability.

The hydraulic boundary conditions of permeable top and impermeable bottom are used for the most common case (a drainage blanket at the base of the embankment and a clay deposit with impermeable bottom) of 2D consolidation analysis.

The charts presented take into account the relative layer thickness of the clay layer, embankment geometry, cross-anisotropic permeability and construction period.

The paper reveals that the post-construction settlement becomes insignificant for relatively thick deposit with permeability in the horizontal direction much higher than that in the vertical direction.
Swelling-shrinking properties of weathered clayey soils associated with shallow landslides
Authors: Meisina Claudia
Published: November 2007

This paper outlines the geological and geotechnical characteristics of colluvial clayey soils, originating from the weathering and down-slope transportation of the Complesso Caotico and Argille Varicolori, in relation to swelling-shrinkage. Shallow earth translational slides and earth flows, affecting such colluvial soils, are a recurrent problem causing damage to infrastructures. Three zones, in the Oltrepo Pavese (Northern Apennines, Italy), representative of areas where shallow landslides occur were selected for study. Geotechnical site investigation consisted of open trial pits, the weathering profile description and the collection of disturbed and undisturbed samples. In addition to the mineralogical and geotechnical tests (index properties and matrix suction determination), the samples were submitted to the methylene blue adsorption test, swelling pressure and percentage of volume change tests. The variation of the soil suction on drying and wetting paths have been also studied. The soil profiles, showing the characteristics of the colluvium, the weathered bedrock and the bedrock, do not highlighta mineralogical evolution with depth. The samples are characterised by a very high and high swelling-shrinking potential. The depth of the ‘active zone’ ranges between 0.8 m and 1.8 m and corresponds to the depth of the shallow landslides. The soils are saturated or quasi saturated for most of the year and even for high suction. Starting from these conditions, the soils tend to follow drying paths. The shrinkage is very strong in the dry season. Due to shrinkage cracks water flow rapidly through the cracks into the subsoil. This result in avery rapid response on precipitation events and in a lubrication of clay along the fissures, thus encouraging movement downhill.
Evaluation of groundwater chemistry affected by an abandoned metal mine within a dam construction site, South Korea
Authors: Lee J.Y. , Choi J.C. , Yi M.J. , Kim J.W. , Cheon J.Y. , Lee K.K.
Published: November 2007

Groundwater chemistry in and around an abandoned metal mine within a large dam construction site was evaluated. For this purpose, a total of 50 groundwater samples were collected and chemically analysed for major ions and toxic metals. The pHs of the groundwaters were near neutral to slightly basic, with an apparent increase along the flow direction away from the mine waste dump. Higher values of electrical conductivity with a mean of 532 μS cm
−1
were observed in the mine area. Dissolved oxygen concentrations over 5 mg l
−1
clearly indicated an oxygenated groundwater environment. The high concentration of sulphate was derived from weathering and oxidation of sulphide minerals. Hydrochemistry of the groundwater samples is characterized by the relatively significant enrichment of Ca
2+
and SO
4
2−
. Results of factor analysis also indicated that the dominant mechanisms or continuing processes affecting the distribution of the chemical parameters in the study area are various geochemical reactions including dissolution of sulphide and carbonate minerals, and removal of calcium and sulphate by dilution through mixing with Ca
2+
− and SO
4
2−
-poor groundwaters. In the mine area, substantial groundwater contamination by toxic metals including Zn, Al, Fe and Mn was observed. Most of the toxic metals decreased gradually or dramatically with distance from the mine, although some metals were also found in high concentrations in the downstream areas. Compared with the contamination levels of the surrounding farmland soils and stream sediments, the levels of contamination of groundwater by toxic metals were relatively low. The low concentrations are ascribed to the high pH and highly oxygenated conditions, which reduce toxic metal mobility. Significant groundwater contamination with toxic metals was strictly limited within the immediate vicinity of the mine waste dump but the ubiquitous distribution of the toxic metals with slightly elevated levels all over the study area may be attributed to the same geology and mineralogy as in the mine area.
High concrete dam on serpentinite
Authors: Glawe Ulrich , Linard Jack
Published: November 2007

This paper presents the geological conditions encountered at the site of the proposedKusan-3 hydropower project located in South Kalimantan, Indonesia and their influence on the tender design of the 100 m high gravity dam. The rock types identified during investigation of the dam foundation are pyroxenite, serpentinite, peridotite and diorite. Serpentinite, which extends over nearly 30% of the dam base, is well known to be a questionable foundation material. On the basis of this qualitativeassessment, attention was focused primarily on theserpentinite. Both laboratory and
in situ
field tests were carried out on the serpentinite. An estimate of the shear strength and the deformability of the rock mass were developed from the laboratory data, taking scale effects and discontinuity characteristics into account. In addition, applying the Geological Strength Index system to quantify the physical parameters of the serpentinite provided satisfactory confirmation of the selected values. The layout and the design of the dam have been developed for the derived rock mass properties and adapted to accommodate the complex, but optimum arrangement of the diversion works, the spillway and the power intake. It is concluded that the proposed Kusan-3 RCC dam can be safely constructed on the serpentinite and on the other crystalline rocks at the site.
The application of Time-Lapse Microgravity for the Investigation and Monitoring of Subsidence at Northwich, Cheshire
Authors: Branston M.W. , Styles P.
Published: November 2007

Peter Street is an area of terraced houses in Northwich suffering from subsidence, thought to be related to salt extraction in the 19th century. Microgravity and resistivity profiling have been used as non-invasive techniques to investigate the cause of this subsidence. Repeat (or time-lapse) microgravity has been used to assess the stability and evolution of the low-density areas. Time-lapse microgravity uses the characteristics of anomaly size and gradient to track the development of cavities as they propagate to the surface. It is possible to monitor the change in gravity with time and to model the increase in cavity volume and/or depth. A gravity low was found to be coincident with the area experiencing subsidence. Integratedmodelling techniques including Euler deconvolution, Cordell & Henderson inversion and GRAVMAG modelling have been used to investigate the depth and size of the body responsible for this anomaly. Resistivity imaging has been used to investigate the conductivity of the near surface and constrain the gravity models. Results from both techniques suggest that low density ground is now present at a depth of 3–4 m below the surface in the subsidence affected area. The use of time-lapse microgravity has shown that there has been an upwardmigration of a low-density zone at gravity anomaly C over the monitoring period.
Effect of soaking period and surcharge load on resilient modulus and California bearing ratio of gypsiferous soils
Authors: Razouki Sabah S. , Kuttah Dina K.
Published: November 2007

Aclay of CH group according to the unified soil classification system (or CV clay according to BS 5930) with about 33% gypsum contentwas tested in the laboratory for the resilient modulus using the ultrasonic wave propagation technique. Forty-eight California bearing ratio (CBR) soil samples were compacted at the optimum moisture content and 95% of modified AASHTO compaction. For each soaking period of 0, 4, 7, 15, 30, 60, 120 and 180 days, three pairs of samples were loaded at 45, 178 and 312 N surcharge load, respectively. The resilient modulus (
M
R
) of the gypsiferous soil tested was determined using CBR soil samples before and after each soaking period, and the following observations were made: (1) soakingresults in a progressive decrease in
M
R
with increasing soaking period; (2) after 180 days soaking the resilient modulus decreased by 92%, 85% and 80% relative to the unsoaked condition for CBR samples under surcharge loads of 45, 178, and 312 N, respectively. Furthermore, a strong linear correlation between the resilient modulus and soaked CBR was found. An empirical equation has been developed relating
M
R
at any soaking period to the unsoaked condition, taking into account the effect of soaking period and surcharge load.
Determination of the acceptability of glacial tills for earthworks
Authors: Winter M.G.
Published: November 2007

Earthwork acceptability of glacial tills presents some unique engineering challenges. These largely derive from the inherent variability and broad particle size range of till materials. This paper presents the methods now commonly used in much of the UK, but especially Scotland, for dealing with glacial tills. The MCV test forms the basis of the approach and the operation of the test is given in outline form whereas applications of MCV tests are described in detail. In particular, details of a method for forecasting the MCV and predicting the moisture content up to 1 year in advance are given. However, when the percentage of larger particles is high and conventional laboratory tests become inappropriate, alternative means of test are required. The circumstances in which this may be the case are detailed and an outline strategy for dealing with such materials is described. The paper is written in terms of the UK Specification. In addition, as the Irish Specification is based on the UK Specification, the information should be simply applied in Ireland. However, one or two issues have arisen that may work against that end. The basic information given in the paper should also be applicable to countries with alternative approaches to the specification of materials for earthworks, albeit with modification as appropriate. The effects of the introduction of design and build and design, build, finance and operate forms of procurement on earthworks are also described, and opportunities for innovative approaches to waste management in the earthworks environment are also discussed.
Hazard assessment for progressive, weathering-related breakdown of excavated rockslopes
Authors: Nicholson D. T.
Published: November 2007

There is currently no systematic approach for the evaluation of shallow, weathering-related breakdown of excavated rockslopes. The
ad hoc
approach often adopted to assess this type of rockslope deterioration gives rise to unplanned resource requirements or, alternatively, results in resource wastage because of over-design or excessive and unnecessary monitoring and inspection. A field investigation of over 200 slopes in the UK found deterioration to be widespread in excavated road cuts and disused quarry slopes. Deterioration is manifest in a range of erosional processes, which are classified according to constituent material size, relative velocity of movement and frequency of occurrence. These erosional processes correlate well with the type of rock mass in which they occur and result in a range of distinctive small-scale erosional and depositional slope forms. A new, three-stage approach to slope hazard assessment, Rockslope Deterioration Assessment (RDA), is proposed, which addresses shallow, small-scale weathering-related erosion of rockslopes. In RDA stage one, rockslope susceptibility to deterioration is assessed via the application of ratings to intrinsic and extrinsic influences and controls on deterioration. In stage two, the nature of the likely deterioration hazard is qualitatively reviewed with reference to rock mass type and slope morphology. In stage three, guidance on appropriate mitigation is provided, based on the findings of stages one and two.
The first engineering geological publication in the UK?
Authors: Culshaw M.G.
Published: November 2007

Almost all engineering geological publications in the United Kingdom date from the 20th and 21st centuries. However, a long forgotten Memoir of the then Geological Survey of the United Kingdom described the soils and subsoils of London and the surrounding area in terms of foundation conditions associated with natural and artificial soils, geological hazards and groundwater pollution. This Memoir was first published in 1897 and was accompanied by a simple form of engineering geological map, in colour, based on lithological units rather than stratigraphical ones. The Memoir sold out but was revised and republished as a second edition in 1906. Nothing similar was published by the Survey until the 1970’s and a modern engineering geological description of the London area was not published until 1997.
Seeking the research frontiers for UK engineering geology
Authors: Griffiths J. S. , Culshaw M. G.
Published: November 2007

Anumber of weaknesses have previously been identified that could curtail future development of engineering geology as an independent subject. In the UK one way to guarantee the continued vigour of the subject and provide a continual stream of new recruits into the field will be to ensure that engineering geology has a thriving research culture. At present, the UK research councils provide little support for research in engineering geology, partly because the potential areas of research either are ill-defined or have now been taken over by other disciplines, such as soil and/or rock mechanics. However, many areas where research is needed in the subject can be identified. The concern is that unless engineering geology is willing to push forward its own research frontiers, the very real possibility exists that the discipline will be subsumed as a minor branch of geotechnical engineering.
Analysis of flows from a large Carboniferous Limestone drainage adit, Derbyshire, England
Authors: Shepley M.G.
Published: November 2007

The flow hydrograph of a large mine drainage adit, the Meerbrook Sough, has been analysed to determine the large-scale hydraulic behaviour of the artificially drained Carboniferous Limestone aquifer. A conceptual model has been constructed using available hydrological and hydrogeological data. The analysis shows that the Carboniferous Limestone can behave at a larger scale as a dominantly diffuse flow system in which storage processes are also important. The conceptual model of groundwater flow is supported by numerical modelling. The dominance of a diffuse flow response is attributed to the large-scale dewatering below the base level of drainage, which has disconnected a significant proportion of the natural conduit flow system. The storage process that provides the relatively reliable flow response from the Carboniferous Limestone is discussed with reference to hydrogeological field data and historical and industrial archaeological sources on the mining in Derbyshire.
Landslides in the Wushan–Zigui region of the Three Gorges, China
Authors: Fourniadis I.G. , Liu J.G.
Published: November 2007

Landsliding is the most widespread natural hazard in the Three Gorges region of China. The occurrence of landslides can lead to relocation of towns, blocking of roads, and casualties as a result of the destruction of houses and factories. This paper outlines the main landslide types encountered in Wushan–Zigui, and some of the more catastrophic slope failures to have occurred in the area in recent years.
Improved material specifications for unsealed roads
Authors: Paige-Green P.
Published: November 2007

Performance-related specifications for the selection of gravel materials for use in unsealed roads were developed in South Africa in the late 1980s along with associated deterioration models. The implementation of these has shown that, when the material fully complies with these specifications, and the materials are compacted to a high density, the actual performance of the road is even better than predicted by the models. These specifications have subsequently been tested and implemented in other countries in the southern African region. However, whereas in South Africa test methods are based upon ASTM methods, the test methods used in other countries are often based upon the British Standard methods. The inherent differences in these test methods need to be taken into account so that the specifications can be effectively applied. A revised material selection guide and performance prediction chart have been developed for use when the materials are tested using the British Standard test methods.
A method for the analysis of tracer tests in groundwater
Authors: Carlier E. , Boulemia C.
Published: November 2007

The method presented enables determination of the turnover time, the coefficient of dispersion and the dispersivity from dye tracer tests. This method was first tested on a column of sand, which is a medium with single porosity. Then, the method was tested on chalk, a dual porosity medium, and modified because the coefficient of dispersion depends on the location of the centre of plume. Comparison between experimental and computed data leads to conclusions about the validity of the method.
Factors affecting the groundwater system around an underground LPG storage cavern
Authors: Ko Kyung-Seok , Chang Ho Wan , Kim Taehee , Lee Kang-Kun
Published: November 2007

Natural and artificial factors affecting groundwater flow and transport in the vicinity of an LPG storage site were examined to understand the groundwater flow and transportregime around LPG storage caverns. The cross-correlation analysis results showed that the 11-year monitoring data of groundwater head and seepage water into caverns were mainly controlled by rainfall and cavern operation pressure. The result of seepage rate being mainly controlled by operation pressure support the dependence on operation pressure rather than rainfall and microbial clogging. Hydrogeochemical analysis results in the site showed the influence of sodium hypochlorite (NaOCl), used in disinfection activity to remove microbial clogging around caverns and water curtains. Due to the chemical characteristics of NaOCl, the groundwater compositions of wells around caverns selectively showed high pH, sodium, and chloride concentrations. Heterogeneous distribution of sodium and chloride regardless of distance from water curtains and caverns implied the channelling effect of the fractured medium. The faults and associated fractures, which act as groundwater conduits in the site, are considered to be themain factors causing the hydrochemical heterogeneity. The distribution of hydrogeochemical constituents in groundwater shows that the major part of groundwater flow and transport occursfrom structurally formed high-recharge zones to cavern seepage zones.
Engineering geomorphology for road design in unstable mountainous areas: lessons learnt after 25 years in Nepal
Authors: Hearn G.J.
Published: November 2007

Twenty-five years after the publication of the pioneering work in the field of mountain road engineering geomorphology by D. Brunsden, J. C. Doornkamp, D. K. C. Jones and others, the design and construction performance of the Dharan-Dhankuta road in Nepal vindicates the approach that was applied in this geotechnically challenging part of the Himalayas. The use of engineering geomorphology as a forerunner to more detailed geotechnical studies during design and construction proved an extremely worthwhile exercise. Despite this, the wider use of engineering geomorphology in Nepal since then has been disappointingly low. There are instances where a lack of engineering geological or geomorphological appreciation has led to recurrent problems, leading to design and even alignment modifications. Elsewhere, engineering geology has provided sufficient information and interpretation to enable design to proceed effectively, and the evaluation of slope and drainage hazards as past, recurrent and potential future risk elements has required geomorphological assessment as the critical path activity. However, rapid geomorphological reconnaissance mapping remains a largely judgemental exercise, and one that still suffers from outcome uncertainty despite the passage of 25 years of applied Himalayan geomorphology. Nevertheless, as an observational and interpretative technique that attempts to combine past geology with current and predicted future geomorphology, it should be a critical element in any mountain road engineer’s geological tool box. The future for engineering geomorphology is reliant on a greater integration between landforms, processes and hazards, and the development of a wider appreciation and commitment in both the training and industrial spheres.
Assessing subsoil permeability for groundwater vulnerability
Authors: Swartz M. , Misstear B.D.R. , Daly D. , Farrell E.R.
Published: November 2007

Groundwater vulnerability assessment is a key element of any groundwater protection scheme. In Ireland, groundwater vulnerability is determined mainly according to the thickness and permeability of the subsoils (glacial tills and other superficial deposits). The relative permeabilities of the subsoils are assessed qualitatively as high, moderate or low. To improve the robustness of the groundwater protection scheme, research was carried out into subsoil properties with the aims of refining the permeability ratings, and of improving the way in which subsoil permeability classes are assigned. This research focused on subsoils in the low and moderate permeability categories, mainly tills. Important issues investigated were the relationship between permeability and the grain size distribution of the subsoil, description of subsoils for permeability classification, correlation between permeability and indicators of aquifer recharge, and suitable field and laboratory methods for measuring subsoil permeability. A standard system for describing subsoils was selected, namely BS5930:1999, the choice being influenced by the familiarity of this system among the main users of the vulnerability maps. Analysis of subsoil field descriptions and grain size data indicate that those samples identified as ‘CLAY’ on the basis of BS 5930 correspond to the low permeability category, and tend to have more than 13% clay size particles. The permeability values obtained from each method are compared and indicate that the numerical boundary between moderate and low permeability lies in the region of 10
−9
m/s. Differences between the results from laboratory and various field permeability test methods can be explained by differences in scale and by the presence of discontinuities. The research was successful in refining the permeability ratings and thereby in making the vulnerability maps more defensible against possible challenges. This research has improved the way permeability maps are produced in Ireland, and may prove useful in other countries where permeability data are scarce and mapping relies largely on field assessment of subsoils.
Analysing step-drawdown tests in heterogeneous aquifers
Authors: Karami Gholam H. , Younger Paul L.
Published: November 2007

All existing methods for analysing step-drawdown test data assume that the aquifer is homogeneous, whereas most real aquifers are heterogeneous. Failure to account for such heterogeneity can lead to erroneous mis-interpretation of step-drawdown test results, which may in turn result in expensive over- or under-design of long-term pumping plant. This paper reports a new method for analysing step-drawdown data which not only takes heterogeneity into account, but which also turns out to be simpler and more robust than existing methods even where the aquifer is relatively homogeneous. The new method is equally applicable to confined, leaky, and unconfined aquifers. The heart of this method is a simple data transformation procedure (which we term ‘homogenization of drawdown records’), based on an obvious logic, that unambiguously separates aquifer losses and well losses. As such, the new method directly calculates the well loss in the pumping well without recourse to the equations and coefficients upon which the existingmethods of analysis are based. Extending the same logic, it is apparent that well loss can also be quantified using data from constant-rate pumping tests. The new method not only yields more consistent and reliable results than existing methods, but also enhances conceptual understanding of drawdown processes and is sufficiently simple that it can be implemented rapidly by manual calculations, allowing analysis of test data in the field, even while pumping continues.
Mineralogical and petrological evidence for the hydrogeological characteristics of the Tsukiyoshi Fault, Japan
Authors: Hama K. , Amano K. , Metcalfe R. , Yoshida H. , Iwatsuki T. , Milodowski A.E. , Gillespie M.R.
Published: November 2007

Generic approaches for determining the spatial and temporal variability of a fault's hydrogeological properties are being developed by studying the reversed Tsukiyoshi Fault at Tono, central Japan. This fault is associated with zones of deformation/damage that are sometimes wider than the fault's displacement. The hydraulic characteristics probably vary laterally over metres to tens of metres and the hanging wall and foot wall have different hydraulic properties. It is also possible that some of these properties may have changed over time, due to physical processes and/or to water/rock interactions, even at relatively low-temperatures and pressures (to a few tens of degrees centigrade and hundreds of bars). It is suggested that mineralogical and structural data can be used to estimate the most transmissive conditions within a fault in the past. These estimates can then be used to select conservative (‘worst-case’) fault parameters for assessing the future safety of underground waste repositories. Such information can also be used to design a repository to avoid faults with permeable crush zones. The study demonstrates the value of integrating detailed mineralogical and petrological studies into a borehole drilling programme for characterizing the hydraulic properties of faults.
Rock mass properties for engineering design
Authors: Pine R.J. , Harrison J.P.
Published: November 2007

The determination of rock mass properties for engineering design is considered from twoperspectives. These are
in-situ
measurement, including classification-based methods, and the limitations of the classification approach.

Several measurement methods are available which will give useful results, if used appropriately. The choice of different methods will depend on the nature of therock mass. The required accuracy should be considered realistically and, in many cases, high levels of accuracy are not, in fact, necessary. Examples are included, which show how the mass strengths of mine pillars were determined with acceptable accuracy using well known rock mass classification schemes, modified as necessary to accommodate local conditions.

Rock mass classification is a widely used, economical and extremely useful basis for determining properties, but there are dangers in uncritical application. The classification methodology is critically examined, and the use of multivariate statistics applied in a multi-dimensional space is considered to optimize the usefulness of the measured data.
Direct shear tests on an uncemented, and a very slightly cemented, locked sand
Authors: Cresswell A.W. , Barton M.E.
Published: November 2007

Direct shear tests up to 10 MPa normal stress have been carried out on two sets of intact block samples taken from the Reigate Silver Sand (part of the Cretaceous Folkestone Sand formation). One set (called A2) is completely free from any trace of authigenic cementation but its well interlocked fabric gives it a small, measurable cohesive strength. The other set (A3) possesses a trace of iron oxide and clay cementing and is noticeably more cohesive and easier to sample. Both sets of samples show a power law form of shear strength envelope but vary in their dilatancy characteristics. Observations have been made of the macro- and microfabric features produced during and at the end of the tests. These indicate that stress rotation is accompanied by microscopic rotation of blocks of intact sand during shear with buckling in the shear zone. Study of the literature on dense sands and sandstones suggests that a tendency for such block behaviour is a common feature of arenaceous materials but that it is only with locked sands that this mechanism is displayed to best advantage. Cementation increases the resistance of the blocks to rotation. Saturated samples of A3 have a slightly lower shear strength and it is inferred that the presence of moisture reduces the buckling resistance of the blocks.
A note on the geochemical aspects of the Harrogate mineral waters
Authors: Brassington F.C.
Published: November 2007

Three new water supply boreholes have been drilled in Harrogate and extend the available information on the hydrogeology of the mineral water springs. The water chemistry, combined with the geological evidence, shows that they tap waterat the opposite ends of the mineralized groundwater evolution system. Groundwater chemistry in the recharge area is available for the first time and there is new evidence that the deep migration of mineralized waters extends further than has been found hitherto. A conceptual model for the groundwater circulation system has been developed and a possible source of the high sodium chloride content is postulated.
Methodology to identify badly weathering limestone using geochemistry: case study on the Lower Globigerina Limestone of the Maltese islands
Authors: Cassar JoAnn , Vella Alfred J.
Published: November 2007

This paper proposes a new objective method to classify building limestone into types of varying durability working on samples that are visually identical in appearance. Geochemical data were obtained for 90 samples of the Lower Globigerina Limestone of the Maltese islands. Multivariate analyses, including cluster analysis, principal components analysis and discriminant analysis allowed the identification of variables SiO
2
, Al
2
O
3
, K
2
O, TiO
2
, Fe
2
O
3
as indicators to distinguish between more durable ‘franka’ limestone and the less durable facies locally called ‘soll’. This hypothesis was confirmed by differences in geochemical data from samples of both weathered and unweathered stone taken from abandoned quarry faces. In the less durable ‘soll’, SiO
2
concentrations are >3.4±0.3%, Al
2
O
3
>0.78±0.05%, K
2
O >0.13±0.01%, TiO
2
>0.06±0.002% and Fe
2
O
3
>0.47±0.02%. However, some overlap occurs between the two stone types for all five components, demarcating another stone type we designated as ‘intermediate’. The geochemical differences are reflected in mineralogical data and in acid-insoluble residues. This geochemical method is simple and innovative. It can be used to identify newly extracted limestone for use in building and also for replacement of deteriorated stones in old buildings.
Groundwater circulation patterns and isotope geochemistry in the Chalk of Northern Ireland
Authors: Barnes S. , Parnell J. , Ruffell A.H. , Kalin R.M.
Published: November 2007

The Cretaceous Chalk or Ulster White Limestone Formation (UWLF) of Northern Ireland predominantly occurs as a fracture flow aquifer that exhibits both deep artesian conditions at subcrop, and shallow karstic behaviour at outcrop. The UWLF is underlain by impermeable Triassic/Jurassic mudstones and overlain by Tertiary basalt lavas. Aconceptual regional groundwater circulation model has been developed using limited hydraulic head information. This has been tested using isotope geochemistry.

Springs draining the outcrop section of the aquifer produce ‘recent’ waters with abundant modern carbon. Stable isotopes and hydrochemistry have demonstrated that surface runoff is the predominant source of recharge to the outcrop region (as opposed to basalt leakage recharge). UWLF spring water chemistry is often similar to that of the potential recharge waters. Deep regional flow in the aquifer can occur by seepage from the outcrop areas, but limited ‘outlet’ potential means that circulation is slow and distinct hydrochemical evolution occurs. Radiocarbon ages for this groundwater have beendetermined at between 10 000 years and 20 000 years.

Isotope geochemistry in the UWLF of Northern Ireland thus provides a powerful method for differentiating groundwaters in terms of their interaction with rock,their circulation route and their age. These have major implications for resource modelling and vulnerability.
Field techniques for the economic and geotechnical evaluation of mining property for opencast mine design, Knob Lake, Quebec
Authors: Nichols Lee
Published: November 2007

The experience of the first twelve years of mining operations at Knob Lake, Quebec, has shown that severe ground-water problems exist in the mining area. These conditions are a result of a high water-table, active recharge rates and high permeability values of the geological formations, which in turn have enhanced the instability of artificial slopes. In order to account for these factors in obtaining optimum mine-design criteria, a detailed geotechnical programme combining hydrological, geohydrological, geochemical and soil mechanics investigations with the standard development programme of economic property evaluation is proving to be an efficient framework within which to conduct these investigations. More specifically, the hydrological programme is focused on water-balance studies for selected ground-water basins, while the geohydrology studies encompass water-table and pore-pressure measurements and the construction of flow nets for both ground-water basins and local areas (ore zones). The geochemical programme, now in its initial stages, is being invoked to define ground-water flow by utilizing certain minor and trace elements as natural ground-water tags. Chemical equilibrium of the major elements dissolved in the ground-water, with the minerals in the aquifers and aquicludes, may assist in defining ground-water flow domains or boundary conditions and residence times, in distinguishing between steady and non-steady states and, finally, in proportioning water-well discharges. The soil mechanics investigations are centred on obtaining shear-strength data, studying the distribution of discontinuities and defining slip geometries. An outline of some of these studies and case studies of some slope features are presented.
Small-scale drilling operations for research purposes
Authors: Farmer Noah , Jones John Michael , Murchison Duncan George
Published: November 2007

Two easily transportable drills of Canadian design costing £875 have been intensively operated over a nine-month period and have proved valuable for sampling, stratigraphical control and teaching purposes. A comprehensive range of accessories is available and includes recovery taps, rod spears and core fishers as well as a variety of bits and reaming shells. The more powerful drill will take cores of approximately one inch diameter in successions of mixed sediments to depths greater than 250 ft. Penetration rates, even in hard, compact rocks, usually exceed 1 ft/5 min and average drilling rates of 40 ft/8 h shift for coring at all depths can easily be achieved. Core recovery normally lies between 80 and 85 per cent with the main losses in mudstones and fireclays. Superficial deposits have not presented major difficulties and casing to rockhead at 50 ft is quite feasible. One thousand feet of strata have been drilled at a cost of 3$ 9d per ft, exclusive of any charge for labour, which has been provided by teaching and research staff of the Organic Geochemistry Unit of the Department of Geology, University of Newcastle upon Tyne.
Engineering geology and soil mechanics
Authors: Glossop Rudolph
Published: November 2007

T
he formation
and success of the Engineering Group of the Geological Society is a symptom of the ever-increasing influence of geology on civil engineering which has become evident in recent years. This liaison between civil engineers and geologists is important, but it is in its early stages, and there are still problems in the training, the status and the duties of the engineering geologist which remain to be solved. Their solution is an urgent matter, for universities are now starting courses in 'engineering geology', and there is a danger that some may produce graduates who are neither fully competent engineers nor fully competent geologists.

In the near future the Group will hold a conference devoted to this question, but in the meantime I should like to express my own views, if for no better reason than that they may lead you to think about it and be ready to take part in such a discussion.

We all know that William Smith was a civil engineer, but the fact remains that until comparatively recently geology has not played an important part in civil engineering practice. This is obvious from an examination of the published literature. It is true that early in the 19th century engineers who were then chiefly concerned with the construction of canals, roads and the early railways, paid a good deal of attention to geology, as can be seen by looking through old volumes of the
Annales des Fonts et Chaussées
, and to a lesser degree, the
Proceedings
Some engineering properties of cement-stabilized Keuper Marl with particular reference to rapid and repeated compression tests
Authors: Dunn Charles Scott , Obi Boniface Chukwukadibia Akabogu
Published: November 2007

A review of relevant properties of Keuper Marl indicates that much of the Marl is likely to be suitable for cement stabilization, exceptions being marls which are either too plastic or contain deleterious proportions of sulphates.

The results of static, rapid and repeated compression tests carried out on a 'typical' marl stabilized with cement are reported. The stiffness of the material as measured by the modulus of deformation is shown to be a function of cement content, moulding moisture content, rate of strain and stress history. Repeated load tests showed that when the intensity of stress applied was 65 per cent of the initial compressive strength, fatigue failure was imminent after 10
4
applications of load. Of particular significance was the fact that the modulus of resilient deformation was independent of the number of load cycles applied and sensibly constant over a range of stress intensities. Values of Poisson's ratio were of the low order of 0·04 to 0·20 and increased rapidly as samples approached failure.

The marl containing 10 per cent cement had a 7-day compressive strength of the order of 300 lb/sq in and would therefore fail to comply with the Ministry of Transport's proposed new specifications requiring 400 lb/sq in. It is concluded that although the stabilized marl may not be acceptable for road base construction, it should serve satisfactorily for sub-bases.

Two construction problems previously encountered when stabilizing Keuper Marl, are discussed and suggestions made for overcoming them.
The effect of geological features on the occurrence of gas outburst fractures in the East Midland Coalfield
Authors: Arscott Raymond Lyndon , Hackett Peter
Published: November 2007

The phenomenon of gas outbursts from the floor of excavations in the East Midlands Coalfield is examined and their general features are described.

An attempt is made to correlate the distinct grouping of the fractures and their uniform directional tendency with the known geological features of the area. A series of underground investigations allied to laboratory work and surveys of previous literature indicate that the general structural geology of the area controls the occurrence of the fractures.
The mineralogy of tropical weathering illustrated by some west Malaysian soils
Authors: West Graham , Dumbleton Michael John
Published: November 2007

The mineralogy of the processes leading to the formation of soils by the tropical weathering and leaching of rocks is reviewed, and illustrated by the results of an investigation into the formation, mineralogy and plasticity properties of some soils formed on basalt, granite, shale and sandstone in west Malaysia.

It is shown that hydrolysis followed by differential solution can account for the formation of the samples studied. Kaolinite was always present and generally the dominant clay mineral, although it gave place to gibbsite under severe weathering, and illite was also present in some of the less weathered soils on granite and shale. Quartz was prominent in soils on granite and sedimentary rocks, which are rich in this mineral. Iron oxide generally occurred, usually as goethite in the soils but as hematite in the nodules which were generally present in the soils selected for study, although gibbsite (hydrated aluminium oxide) was the main constituent of the nodules in one case. The observed mineralogical composition and clay content of the soils are consistent with the range of plasticity properties observed. The activity of some soils was reduced by the presence of gibbsite or goethite in the clay-sized fraction.
An approach to the simulation of mining subsidence phenomena in an elastic, layered model
Authors: Rankilor Peter Richard
Published: November 2007

The author comments on the background to model-analysis of mining problems, and describes the use of urethane rubber in the construction of a layered model simulating strata over mine workings. The unique properties of this rubber allow models to be constructed with layers of varying moduli, and needing only to be subject to a gravitational loading of 1g to be activated. The properties of the material allow models to be used many times, over long periods, and can be used to observe 'dynamic' development of mining and tectonic features. In the dynamic model described, the development of a full subsidence profile was observed and calculations showed it to be realistic with respect to equations developed by the National Coal Board to describe observed subsidence curves.

Previous experimental work by other researchers using elastic homogeneous models has yielded model 'angles-of-draw' in the region of 45°. In this paper the author describes angles-of-draw below 35° and also the subsidence development profile of the model in relation to those observed for some European mines.

The author concludes by suggesting possible future applications for this type of model work.