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About this book

This book is one out six IAEG XIII Congress and AEG 61st Annual Meeting proceeding volumes, and deals with topics related to the geotechnical and environmental site characterization.

The theme of the IAEG/AEG Meeting, held in San Francisco from September 17-21, 2018, is Engineering Geology for a Sustainable World. The meeting proceedings analyze the dynamic role of engineering geology in our changing world. The meeting topics and subject areas of the six volumes are: Slope Stability: Case Histories, Landslide Mapping, Emerging Technologies; Geotechnical and Environmental Site Characterization; Mining, Aggregates, Karst; Dams, Tunnels, Groundwater Resources, Climate Change; Geologic Hazards: Earthquakes, Land Subsidence, Coastal Hazards, and Emergency Response; and Advances in Engineering Geology: Education, Soil and Rock Properties, Modeling.

Table of Contents

Frontmatter

Pressuremeter Tests in Russia and Their Application

A series of 12 preboring pressuremeter tests were performed for the foundation design of a tall building in St. Petersburg, Russia. The site is on the North shore of the Neva River Delta. The soil layers at the site consist of Quaternary soft saturated soils of marine, glacial-lake origin and hard Vendian clay. The test procedure was the one recommended by the Russian standard which calls for much longer pressure steps than the ASTM Standard. Modulus of deformation and limit pressure profiles were obtained for 24–40 m depth in the Vendian clay. Such pressuremeter test results are often used for the foundation design of tall buildings.
Anna Shidlovskaya, Anna Timchenko, Jean-Louis Briaud

A Simple Method of Estimating Ground Model Reliability for Linear Infrastructure Projects

The ground model is fundamental to any engineering project with ground structure interaction. Linear infrastructure projects have many forms of ground interaction and ground models are essential. All ground models are hypothetical. Interpolation or extrapolation from known data is required in order to form a prediction of the ground characteristics at any particular location. There is therefore inherent uncertainty in every ground model. The reliability of the ground model may be considered to be a function of (1) the accuracy or reliability of the data on which it based; (2) the quantity of data or ground information available; (3) the geological complexity of the ground from which the data has been obtained and (4) the complexity of the ground response to changes induced by the project. This paper presents a method of assessing ground model reliability for linear infrastructure projects based on an assessment of these four key factors. This method has been applied to three linear infrastructure projects in Australia, which are discussed.
Darren Paul

A Case Study on the Microstructure of Fibrous Peat (West Lake, China)

The classification of peat soils involves a very large number of different types. From a descriptive perspective this is useful, however such a system generates too many options for engineering purposes. The behaviour of organic soils varies based on the quantity and type of organic material present within the soil. The effects of fibre content are particularly important. The West Lake in Hangzhou has been dredged many times during its history to maintain its beauty. During the most recent dredging the sludge from the lake was transported via a 4 km pipeline and deposited inside the Jiangyangfan Reservoir. The organic soil situated in Jiangyangfan Ecopark is a particularly interesting peaty material. The organic sludge was mixed and homogenised during the transportation process, and then settled out within the reservoir. This resulted in a more than 20 m thick peat layer deposited with an uneven surface. The Ecopark buildings were then constructed on top of this in 2008. A combined electron microscope and mechanical study of the microstructure and behaviour of the peat has been used to identify the engineering impact of the presence of relatively small number of fibres within the soil matrix. The fibres within the peat modify its behaviour such that it can no longer be understood within the typical critical state framework for soils. The peat starts to deform plastically under very small levels of applied stress. In addition, it does not display a tension cut-off failure and, ultimately, fails in shear.
Stephen Wilkinson, Chaofa Zhao, Zhongxuan Yang, Kun Pan

Geomechanical Investigation of High Priority Geothermal Strata in the Molasse Basin, Bavaria, Germany

Due to the increasing use of geothermal energy in Bavaria, Germany, over the last years, the practical experience in geothermal plant operation for heat and power generation has shown an evident need for research. Especially questions related to deep geothermal energy need to be answered, and the risk of geothermal exploration in the Molasse Basin and the crystalline rocks in the northern part of Bavaria should be reduced to optimize reservoir engineering. The Molasse Basin, extending along the northern flank of the Alps, represents an alpine foreland basin. Situated south of Munich, the basin offers ideal conditions for the use of hydrothermal geothermal energy. The petrothermal potential in crystalline rock is focused in the northern part of Bavaria. The development and use of this future technology initially requires extensive research but has outstanding future potential. In this context, the determination of rock mechanical parameters is indispensable for the subsequent modelling of hydrothermal and petrothermal reservoirs. For this purpose, laboratory tests were conducted using drilling samples as well as analogue samples from quarries. Based on the results of these experiments a database has been created. This database improves the knowledge of the mechanical properties of representative rock types. Furthermore, the database improves the knowledge about detection of a local stress field, which has major impact on the hydraulic system of the geothermal reservoir. The outcome of this research should increase profitability and minimize risk of geothermal projects.
Martin Potten, Bettina Sellmeier, Elena Mraz, Kurosch Thuro

The Potential Use of Residual Soil from Ribeira Valley (Brazil) in Mitigating Metal Contamination: A Geotechnical Characterization

The incorrect disposal of hazardous waste causes serious problems around the world. For instance, mining waste is one of the main sources of potentially toxic metals in the environment. In the Ribeira Valley region of Brazil, residues generated during lead ore smelting were improperly deposited in the Ribeira de Iguape River and on the soil’s surface without protection. An alternative solution for mitigating local contamination is verifying whether a local residual soil is appropriate to use as a mining waste landfill liner. The soil is sandy silty clay, with a plasticity index of 24%, an optimum water content, wopt, of 26.3% and a maximum dry density, ρdmax, of 1.515 g/cm3 from the Standard Proctor test. Specimens molded at an optimum compaction condition showed hydraulic conductivity of 10−9 m/s and effective shear strength parameters of c′ = 22 kPa and φ′ = 26.8°. The soil is acidic (pH 4.6), exhibits low CEC (41.4 mmolc/dm3) and presents a predominance of negative charges on the particle surface (PZSE 3.6 < pH), favoring cation retention. The hydraulic and mechanical characteristics together with the chemical properties suggest that this soil is a candidate for use as a liner. Further studies are underway to characterize its chemical contaminant retention and to complete the analysis about its suitability for the desired purpose.
Jéssica Pelinsom Marques, Valéria Guimarães Silvestre Rodrigues, Orencio Monje Vilar, Edmundo Rogério Esquivel

New Approach to the Assessment of Buildings Vulnerability in Various Natural and Technogenic Urban Conditions

This paper proposes a new approach for assessing the vulnerability of buildings using relative economic indicators that correspond to the standards and costs for inspection of the technical condition of a building. The total (cumulative) for carrying out works to measure and inspect the building are taken as the main indicator characterizing vulnerability. The analysis allowed identifying the main components forming total costs: category of building complexity, location of the building in engineering-geological conditions, category of work complexity, category of the technical condition of the building (normative/operable/limited operational condition), the number of inspections and inspection prices. Seven different scenarios of cumulative inspection costs that are most characteristic for large cities were considered. The value of total costs for the entire period is equal to the unit of relative economic vulnerability. The approach to assessing the relative economic vulnerability of buildings takes into account the metric, engineering and economic characteristics of the building and the engineering-geological conditions of its location, and is universal, operational and readily available.
V. Burova, E. Karfidova

Geotechnical Characterization of Sands from the Portuguese Continental Shelf to Support the Design of Renewable Energy Converters Installation

Projects for the installation of offshore renewable energy converters usually require the in situ characterization of the marine soils due to the high variability of marine environments, which is caused by the constant interplay between sediments and physical agents. In this regard, the safety of the foundations of these devices is a mandatory issue and it must predict adverse meteorological and oceanographic conditions. This article is part of a geotechnical characterization study of a small sector of the Portuguese continental shelf, very close to a designated area for the installation of offshore renewable energies devices. In order to investigate the mechanical and the physical properties of poorly graded sands (SP) and poorly graded sands with silt (SP-SM), triaxial compression tests (CK0D) were performed on undisturbed samples. The effective friction angles for those sands were 35.2° and 34.5°, respectively.
Joaquim Pombo, Paula F. da Silva, A. Rodrigues

Correlation Between CPT and Screw Driving Sounding (SDS)

Cone penetration test (CPT) is probably the most popular in situ testing method in the world today. Various design parameters, such as undrained strength and relative density, as well as indices for liquefaction assessment, can be derived from the CPT. However, the use of CPT in many roading projects and in subdivision developments may be constrained by the number of tests or project cost; hence, alternative in situ testing technique to supplement the CPT is necessary. Screw Driving Sounding (SDS) is a new in situ test in which a machine drills a screw point into the ground in several loading steps while the attached rod is continuously rotated. During the test, a number of parameters, such as torque, load, speed of penetration and friction, are measured at every rotation of the rod; these provide a robust way of characterising soil stratigraphy. In this paper, the principle of SDS testing is described. SDS tests were performed at various sites in New Zealand where CPT data are available. Then, a side-by-side comparison between CPT and SDS is performed to derive correlations between the CPT tip resistance (qc), sleeve friction (fs) and soil behavior type index (Ic) and the SDS parameters. Based on the results, it is observed that qc correlates well with the penetration energy in SDS while fs and Ic are related to the average torque and change in torque, respectively. The good correlation obtained between CPT and SDS indicates that SDS can supplement CPT results for a more cost-effective geotechnical investigation.
Yasin Mirjafari, Rolando P. Orense, Naoaki Suemasa

Litho-Structural Control on the Geotechnical Properties of Colluvial Deposits, Rio do Sul City, Santa Catarina, Brazil

Mountain regions are characterized by high instability and geodynamic processes which result in a wide variety of mass movement, rockfalls and debris flow or avalanches. Mass movement constitutes one of the major hazard in the Rio do Sul city, northeast Santa Catarina state, Brazil. This work investigates the relationship between lithology, tectonic structures, geotechnical properties and landslides processes in the study area. Results showed that lithological control is expressed in alteration grade of different rocks and materials, which is evident by the higher susceptibility of shales and colluvial deposits to weathering, as well as in clay content, which it is primarily represented by illite in the stratigraphic units. Structural control is marked by two failures and fractures sets that affect all stratigraphic units, with NE–SW as the major strike and NW–SE as the subordinate one. Colluvial deposits present in the study area are the result of landslides processes. Geotechnical properties and shear resistance parameters showed a good correspondence between granulometric texture, which is related with mineral composition of parent rock as well as with weathering and erosion processes. Therefore, it is possible to assume that landsliding in the Rio do Sul city can be explained and predicted by the nature of the geological framework and geotechnical behavior of the rocky masses and soil.
Vanessa Noveletto, Marivaldo S. Nascimento, Murilo S. Espíndola, Vitor S. Müller

Vadose Zone Characterisation for Hydrogeological and Geotechnical Applications

Rapid urbanization is resulting in increased vertical development and use of anthropogenic materials. Geotechnical site investigation is well established in assessing ground conditions, and moisture specifically is a standard descriptor in soil profile logging and is addressed through a variety of laboratory tests. However, changing moisture conditions, occurring in the vadose zone between land surface and the groundwater table, results in highly variable conditions. Noting the presence and variability in moisture is not sufficient to ensure longevity of engineering structures and protection of water resources. Water at partial saturation is proposed to impact the infrastructure and the vadose zone moisture budget as: (A) perching above lower permeability (lower-k) materials; (B) perching as waterlogged lower-k materials above capillary barriered higher-k materials; both resulting in (C) possible imbibition into less saturated low-k materials; or, under further wetting, resulting in (D) lateral interflow under a hydraulic gradient; (E) gravity-driven percolation breaching capillary barriers and resulting in translatory downward flow; or (F) unsaturated fracture flow. All these mechanisms combine to result in complex moisture implications on infrastructure during project lifecycle, as well as on recharge and contaminant transport rates above the phreatic surface. These are further exacerbated by anthropogenic materials (e.g. made ground) replacing natural materials and infringing on the natural and pre-development subsurface water cycle, as well as climate change, and more elaborate engineering development. Contrary to saturated systems, unsaturated systems result in alternating wetting-drying cycles causing continuous changes in effective stress and redox conditions. The paper addresses some key findings and examples from experiments and case studies.
Matthys A. Dippenaar, J. Louis van Rooy

Evaluation of Geotechnical Parameters of Slopes at Blumenau, Santa Catarina, Brazil

The state of Santa Catarina, Brazil, has climatic, biological, geomorphological and geological characteristics that contribute directly to the occurrence of landslides. From the geological point of view, colluvial materials resulting from landsliding deposited in the lower parts of the slopes are denominated as hillslope deposits although they do not necessarily originate from the same rock. This study evaluated the geotechnical parameters of the slopes at Blumenau, where intense rainfalls and potentially unstable soils are present on steep hillsides and give rise to unstable colluvial slopes below. These factors resulted in a large number of slopes covered by colluvial deposits. However, in geotechnical mapping these kinds of materials are treated as “hillslope deposits” units with similar behaviors even though they have different geological-geotechnical evolutions and have experienced distinct processes of pedogenesis. The paper covers the classification as colluvial soils and landslides, as well as the use of geotechnical laboratoratory tests and geotechnical mapping. Evaluation of the geotechnical behavior of the soils was based on geotechnical characterization tests and drained direct shear tests in which parameters of cohesion and internal friction angle were obtained. Thus, the goal of this study was to understand the variability of the geotechnical parameters of these colluvial soils that formed as “hillslope deposits” units according to Davison Dias (1995) methodology, so that they could be classified based on their lithotypes. The study results will help in urban planning in Blumenau and contribute to safety and predictability of areas subject to possible landslides.
L. E. C. Alves, M. Espindola, Vitor S. Müller, M. Z. Broetto, R. L. Pizzolo, V. F. Hickel

Engineering Geological Studies for the New Drainage Tunnels of Lisbon

The municipality of Lisbon is currently planning the construction of two drainage tunnels in order to control the periodic flooding that occurs in the city during the winter. The first tunnel is 5 km long with DN5500 diameter, crossing the downtown in a NW-SE direction, and probably will be constructed by TBM. The second tunnel is located in the north part of Lisbon. This tunnel is 1 km long and is planned to be constructed by TBM or by NATM. The first tunnel crosses volcanic rocks and calcareous rocks from the Cretaceous and then detrital and calcareous rocks from Miocene. The second tunnel only intersects Miocene detrital and calcareous rocks constituted mostly by sand, silty sand, clay and biocalcarenite. For engineering geological characterization of alignments of tunnels, a site investigation program was planned and carried out that included boreholes, in situ (SPT, self boring pressumeters tests, packer tests, pumping tests and crosshole test) and laboratory tests (index, oedometer and triaxial compression tests). An integrated analysis of the data obtained from the site investigation works was performed in order to define the engineering geological conditions along the alignments of the tunnels.
Filipe Telmo Jeremias, Rute Ramos, Laura Caldeira

Geological-Geotechnical Studies for the Ore Transport Railway Line “S11D—Sudeste do Pará”, Brazil

In Brazil, the railway transport of iron ore moves large quantities and needs to overcome huge distances between the mining areas and the shipping harbors. As the Brazilian railway network requires renewal and expansion, sound procedures to conduct suitable engineering geology studies are needed. The objectives, methodology, and study phases are presented, focusing on the geological and geotechnical constraints of the terrains crossed by the railway line. These constraints may increase the costs, cause construction delays, or generate difficulties during construction or operation. The new iron ore railway project, “S11D—Ramal Ferroviário Sudeste do Pará” in Brazil, is used as a case study. It is 100 km in length, connecting the new S11D mine to the existing Carajás railway, and hauls the iron ore to a shipping port, the Ponta da Madeira Maritime Terminal. The geological-geotechnical studies developed for the design, and utilized during construction along the S11D railway branch line, are presented and discussed. Several unusual aspects of the engineering geology studies for an excavation, an embankment, a bridge, a tunnel, and for the location of natural granular materials for sub-ballast and ballast layers are presented. It is concluded that continuous improvement of the engineering geology studies is desirable to increase the efficiency of the design, construction, and operation of a railway.
Priscilla H. P. Oliveira, Mário Quinta-Ferreira

Groundwater Nitrate Concentrations and Its Relation to Landcover, Buncombe County, NC

High concentrations of nitrate (NO3) in groundwater can be harmful to human health if ingested, and the primary cause of blue baby syndrome, among other health impacts. In this study, the spatial distribution of NO3 in groundwater for 610 private drinking water wells in Buncombe County, North Carolina was modeled. While NO3 concentration in the sampled wells did not exceed the 10 mg/L limit established by the United States Environmental Protection Agency, some wells had NO3 concentrations approaching this limit (as high as 8.5 mg/L). Kriging interpolation was implemented within a Geographic Information System to predict NO3 concentrations across the county, and a cokriging model using land cover type. Cross validation statistics of root mean square and root mean square standardized for both models were compared and the results showed that the predicted NO3 map was improved when land cover type was integrated into the model. The cokriging interpolated surface with land cover as a covariate had the lowest root mean square (0.979) when compared to the kriging interpolated surface (0.986), indicating a better fit for the model with land cover. NO3 concentrations equal or greater than 2 mg/L were concentrated in 37% hay/pasture land, 34% developed open space, and 29% deciduous forest. The study did not reveal any statistically significant difference in the presence of high NO3 concentration between these landcover types, indicating they all relate to high NO3 content.
Adu Agyemang, Adela Beauty, Arpita Nandi, Ingrid Luffman, Andrew Joyner

Land Change, Soil Degradation Processes, and Landscape Management at the Clarinho River Watershed, Brazil

Since 70’s land changes have been the main driving force inducing environmental degradation in Brazil, particularly in São Paulo State. Considering its very close relationship with landscape evolution, land change pattern and landform classification were analyzed to understand soil degradation in Clarinho watershed (40.89 km2) and propose specific management measures for recovering and conservation. Land change analysis was assessed using LCM toolbox. Landform evaluation was based on Brazilian approach for terrain evaluation. Results show that temporary and permanent soil exposures, due to extensive livestock in naturally fragile areas (i.e. more erodible soils in major surface runoff taxes), are the main triggers in soil degradation. Terrain evaluation also indicates highly fragile landforms due to its relief characteristics and morphogenetic processes. Thick soil profiles which are developed from medium grained rocks, in wide convex slopes, describe the main landforms attributes in inducing degradation. Areas subject to land changes are those in which susceptibility to erosion is high and where records of erosion processes were more expressive. Clarinho watershed large areas need to be treated as “zone for conditioned farming use”, with specific management directives and measures.
José Augusto de Lollo, João V. R. Guerrero, Ana C. P. Abe, Reinaldo Lorandi

Flooding Susceptibility Identification Using the HAND Algorithm Tool Supported by Land Use/Land Cover Data

In Brazilian urban areas, the increases in human activities and extreme climatic event frequencies have resulted in an increase in floods and flooding. Despite Brazilian laws, risk analyses and management are still rare in Brazilian towns due to poor financial and human resources. Hydrological dynamic surveying coupled with land use information can result in quick and low-cost predictions of flood risks, allowing for the identification of critical areas and the design of intervention proposals. In this paper, this methodology is applied to the Caçula stream watershed using the HAND algorithm combined with land use/cover surveys to identify flood and flooding susceptibility. Imagery classification was developed in IDRISI Selva using OLI sensor bands from the Landsat 8 mission with a supervised classification. The HAND calculations resulted in a DEM for the surface flow analysis, including flooding, based on a normalized 3D model. The adopted method provides an understanding of surface process dynamics and the delineation of critical areas and their hierarchy. The results indicate a strong relationship between flooding susceptibility and land changes in the Caçula watershed.
José Augusto de Lollo, Alice N. Marteli, Reinaldo Lorandi

Soil Mixing for Remediation of Contaminated Sites

Soil mixing involves mixing an additive into soil to change the physical or chemical properties of a soil. This geotechnical method is called solidification/stabilization (S/S) treatment when applied for remediation of contaminated soil or sediment. S/S is an established technology for contaminated site remediation. The effectiveness of S/S treatment for a broad variety of soil contaminants is demonstrated by the technology’s high selection rate for remedies at U.S. Superfund sites. According to U.S. Environmental Protection Agency’s 2017 report on Superfund remedies, S/S has been selected for 21% of in situ treatment source control remedies. Most Superfund projects involve contaminated soil. S/S is of increasing interest in in-place or in situ treatment of contaminated soil such as those found at former industrial properties. In situ S/S can prepare “brownfield” sites for redevelopment. S/S treatment protects human health and the environment by immobilizing hazardous constituents within the treated material. Successful treatment is accomplished through physical changes to the soil and often, chemical changes to the hazardous constituents themselves. S/S binding agents are mixed into contaminated soil through a variety of construction techniques including shallow and deep soil mixing. An appreciation of the versatility for the treatment technology can be gained by review of example projects. This paper discusses the principles and application of S/S treatment technology for soil and sediment.
Charles M. Wilk

Harry Ferguson’s Theory of Valley Stress Release in Flat-Lying Sedimentary Rocks

Harry Ferguson developed his theory of valley stress release in flat-lying sedimentary rocks by observing rock characteristics, behavior, and discontinuities in foundation excavations for navigation locks and dams and flood control dams in the Upper Ohio River Basin in the late 1950s and 1960s. He first presented his theory at the AEG Annual Meeting in 1966, then published it in the AEG Bulletin in 1967. Over the past five decades, this theory has provided a unifying framework for world-wide geologic observations and geotechnical interpretations in flat-lying sedimentary rocks. It is appropriate here to review this theory for an international audience and a new generation of engineering geologists. Essential elements of the theory are:
1.
Flat-lying sedimentary rocks near the earth’s surface typically have horizontal stresses greater than vertical stresses corresponding to existing overburden.
 
2.
River (or stream) erosion removes horizontal support from valley walls and vertical support from valley floors.
 
3.
Valley walls deform inward and valley floors deform upward in response to this loss of support.
 
4.
These deformations relieve stresses in rocks of the valley walls and floors.
 
5.
Deformations and stress release produce characteristic patterns and types of fractures and other discontinuities in rocks of valley walls and floors.
 
This theory of valley stress release has both geologic and engineering implications. Geologic implications include a mechanism for on-going valley development independent of tectonic processes; groundwater flow through stress release fractures with associated processes of weathering and alteration plus solution in soluble rocks; mass-wasting processes, e.g., rock slides, rock falls, rock block creep, colluvium development, on valley walls. Engineering implications include layout and interpretation of subsurface exploration programs; foundation depths and treatments; slope and foundation stability; rock excavation and support, both surface and underground; excavation dewatering; dam foundation and abutment grouting.
James V. Hamel

The Characterization of Tropical Peats for Potentially Toxic Metals Adsorption Purposes in an Abandoned Mine Area

Peat has been used as an alternative, low-cost and efficient material capable of retaining metals. Most studies of adsorption have tended to focus on the characterization and adsorption mechanisms of temperate peats rather than tropical ones, therefore there is insufficient data about their characteristics and subsequent use in contaminated areas. The purpose of this study is to assess the chemical characteristics of tropical peats from the Mogi-Guaçu river Basin (Brazil), to evaluate their ability to capture potentially toxic metals in a contaminated mine area in Brazil. The peats were classified as H5–H6 on the Von Post scale of humification and had 48% ash content. The \( {\text{pH}}_{{{\text{H}}_{{\text{2}}} {\text{O}}}} \), ∆pH and the point of zero salt effect (PZSE) for peat 1 was 5.1, −1.0 and 3.6, while for peat 2, the values were 5.9, −2.4 and 3.1, respectively. These data showed materials with low acidity characteristic and a predominance of negative charges, which allows great cation retention. The cation exchange capacity (CEC) was considered high (91.0 and 116.0 cmolc kg−1), especially when considering the organic matter content (520.43 and 510.06 g kg−1). The removal of lead (Pb II) ions from the aqueous solution, investigated under different experimental conditions, revealed a satisfactory efficiency of 1/50, peat/solution ratio. Metals were removed in the descending order Pb > Zn > Cd, and both peats showed similar efficiency of lead sorption in high concentrations. The results show that the tropical peats have good characteristics to be used as alternative adsorbent materials in abandoned and contaminated mining areas.
Isabela Monici Raimondi, Jacqueline Zanin Lima, Valéria Guimarães Silvestre Rodrigues

Carolina Piedmont Groundwater System—Existence of the Transition Zone Between Regolith and Bedrock

The groundwater system in the Carolina Piedmont Province is comprised of two interconnected layers: regolith (residuum/saprolite and weathered rock) overlying fractured crystalline bedrock. The presence of a transition zone (TZ) at the base of the regolith has been interpreted in many areas of the Piedmont and is theorized to be the most permeable part of the system. Most information supporting the existence of the TZ is qualitative and based on observations made during drilling operations. A database of 1410 horizontal conductivity measurements in boreholes at 12 locations in the Piedmont is utilized to quantitatively assess the existence of the TZ. Hydraulic conductivity measurements are grouped into four hydrostratigraphic units based on Standard Penetration Testing (N-Values) and Rock Core Recovery (REC)/Rock Quality Designation (RQD): (1) M1—Soil/Saprolite; N < 50, (2) M2—Saprolite/Weathered Rock; N ≥ 50 or REC < 50%, (3) WF—Partially Weathered/Fractured Rock—TZ; REC ≥ 50% and RQD < 50%, and (4) D/BR—Sound Rock; REC ≥ 85% and RQD ≥ 50%. The 12 locations are grouped into two conceptual models for Piedmont bedrock: layered/foliated bedrock and massive/plutonic bedrock. The following hypothesis was formulated corresponding to the definition of the TZ in the literature: the hydraulic conductivity of the TZ is greater than the hydraulic conductivity of both the overlying regolith and underlying bedrock. The hypothesis was statistically tested on the two conceptual models utilizing a 2-Sample T-Test on the log values of the hydraulic conductivity measurements. Results indicate a TZ of higher hydraulic conductivity exists between regolith and bedrock in both conceptual models.
Malcolm F. Schaeffer

The Consequences of Pyrite Degradation During Construction—UK Perspective

Whilst it is recognised that aggressive ground conditions are associated with a wide range of factors encompassing physical, chemical and biological processes, a high proportion of such problems relate to the presence of sulfate ions in groundwater. Such conditions, which are implicated in the degenerative attack on ground-placed engineering materials and sometimes to volume changes, arise due either to the dissolution of primary sulfate minerals or, more commonly, to the oxidation of sulfide minerals, where in the latter case the groundwater may also become acidic. Notwithstanding that pyrite-bearing strata are distributed widely across the UK and are frequently encountered in foundation works and during the construction and improvement of the arterial highway infrastructure, consideration of the possible adverse implications of pyrite for construction and highway works tends to be overlooked. Furthermore, adverse impacts can develop rapidly during construction in periods of adverse weather, whereas under favourable conditions they would not be suspected. Equipping the design team with the necessary information to identify and address the problems should enable an optimum construction sequence and on-going management during the design life of the structure to be used. British, European and other standards promote good practice in carrying out ground investigations, but often potential problems are not adequately anticipated and catered for. The paper discusses reasons for this and provides guidance on avoiding problems, without the need to preclude the inclusion of the sulfur bearing materials from projects.
M. A. Czerewko, J. C. Cripps

Measuring Fault Displacements Caused by Salt Tectonics Using Marine Geophysical Data

Previously obtained marine geophysical data for proposed Galsi pipeline route from Algeria to Sardinia were used for analysis of buried salt distribution and calculation of associated fault displacements. Crossing convergent African/Nubian–European plate boundary, the southern section of the proposed route also traverses continental shelves and slopes of Algeria and Sardinia, as well as the Algerian abyssal plain of the Western Mediterranean. Deeply buried Messinian-age salt is present throughout this study area. Uncompressible due to the crystal structure, salt is less dense and therefore more buoyant than clastic overburden sediment, having a tendency to flow and form diapiric structures. We conducted analyzes to determine distribution and influence of salt tectonics (halokinesis) on seafloor morphology, focusing on fault displacements above diapiric structures, comparing displacement rates near compressive plate boundary with those within passive margin environments. Seismic reflection sub-bottom profile interpretations, along with age-dated cores, were used to calculate sedimentation rates that led to quantification of rates of movement along faults caused by salt tectonics. Measured and plotted offsets from different resolution seismic profiles were correlated with predicted sediment age at depth of offset. Results show the average estimated rates of salt movement to be 1–2 cm per thousand years, over the top of salt diapirs in the Abyssal Plain, as opposed to 3–5 cm per thousand years near the active convergent plate boundary in the south and near the Sardinian slope to the north where increased stress on salt may be due to the confinement of Sardinian bedrock.
J. Yeakley, Abdul Shakoor, W. Johnson

Environmental and Geological Characters and Stability Problems in the Historic Centre of Matera (South Italy)

The paper briefly illustrates the main environmental and geological characteristics of the ancient historic centre of Matera, where the rupestrian settlements called “Sassi” are located. It illustrates how these characteristics conditioned the development and safeguarding of the old town. The main purpose of the paper is to present how Matera is an extraordinary example of geological and geo-mechanical features conditioning the human settlement development and their stability and safeguard.
Vincenzo Simeone, Angelo Doglioni, Rosa Maria Lacertosa, Francesco Sdao

Naturally Occurring Asbestos in Argentina: A Compilation of Case Studies

In Argentina, asbestos is associated with meta-mafic or meta-ultramafic igneous rocks, mainly serpentinites (or steatized varieties) and amphibolites, and less commonly with dolomitic rocks (in metamorphic and metasomatic domains). Chrysotile, anthophyllite and tremolite-actinolite were identified as the main asbestiform minerals (in the range of respirable particles). Chrysotile occurs mainly in serpentinites or steatized rocks as well as in amphibolites and other host rocks nearby. It appears filling veins, as slip and cross-fiber, generally associated with fissures or shear zones. Amphibole asbestos, mainly from the tremolite–actinolite series and anthophyllite, commonly occurs together with a non-asbestiform counterpart within the same area and deposits. These minerals have been found in talc ores as well as in vermiculite-rich sectors, or filling fissures in meta-mafic and meta-ultramafic rocks. In this compilation, the results of case studies on mines from the provinces of Córdoba, Mendoza and San Juan (Argentina) are summarized, and new data from the western sector of the Pie de Palo Complex are included.
Lescano Leticia, Locati Francisco, Marfil Silvina, Sfragulla Jorge, Bonalumi Aldo, Maiza Pedro

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