Geochemical, mineralogical, and microstructural characteristics of fault rocks and their impact on TBM jamming: a case study

2022 ◽  
Vol 81 (1) ◽  
Author(s):  
Peng Lin ◽  
Tengfei Yu ◽  
Zhenhao Xu ◽  
Ruiqi Shao ◽  
Wenyang Wang
Keyword(s):  
Microstructural Characteristics ◽  
Fault Rocks

scholarly journals The study of the microstructures of clay sediments: a case study of marly sediments from N. Péloponnèse

2018 ◽  
Vol 34 (2) ◽  
pp. 745
Author(s):  
Τ. Α. ΧΡΙΣΤΟΔΟΥΛΟΠΟΥΛΟΥ ◽  
Π. ΤΣΩΛΗ - ΚΑΤΑΓΑ ◽  
Γ. Χ. ΚΟΥΚΗΣ ◽  
Ν. ΚΟΝΤΟΠΟΥΛΟΣ
Keyword(s):  
Mechanical Characteristics ◽  
Structural Characteristics ◽  
Optical Microscope ◽  
Mineralogical Analysis ◽  
Microstructural Characteristics ◽  
Cementing Material ◽  
Physical And Mechanical Characteristics

This paper deals with the systematic study of the microstructural characteristics of clay sediments. These characteristics which are closely connected to the physical and mechanical character of the sediments, are concerned with: a)the structural constituents, b)the microporosity and c)the structural bonds of the sediments. For the determination of the structural characteristics of clay sediments the Scanning Electron Microscope (SEM) and the Optical Microscope are widely used with a supplementary mineralogical analysis of sediment components and the determination of several physical and mechanical characteristics. The observations under the microscope must be focused on the distribution of mineralogical facies and micropores, on the size and shape of clay (micro-)aggregates, as well as on the kind of authigenic facies (e.g. micrite, sparry calcite) which play the role of cementing material. The proposed methodology was applied to the study of the microstructures of marly sediments from Northern Péloponnèse and the following types of microstructures were determined: a)matrix-skeletal, mixed type, coarse dispersed of low orientation, b)matrix, coagulative, medium dispersed of medium orientation and c)crystallized-cementated, fine or medium dispersed of low orientation.

Stochastic modelling of fault gouge zones: implications for fault seal analysis

2019 ◽  
Vol 496 (1) ◽  
pp. 163-197 ◽  
Author(s):  
Neil T. Grant
Keyword(s):  
Stochastic Modelling ◽  
Fault Gouge ◽  
Well Log ◽  
Practical Application ◽  
Fault Rock ◽  
Fault Rocks ◽  
New Approach ◽  
Slip Surfaces ◽  
Modelling Approach

AbstractFault zones are complex, and show considerable variability in both structure and the distribution of associated fault rocks within the fault core: the zone that localizes most strain and displacement. It is the fault-core gouge zone and associated slip surfaces which provide the cross-fault seal when permeable layers are juxtaposed. Predicting the sealing properties of fault gouge zones is difficult but often required when evaluating faults in exploration prospects. A stochastic modelling approach is described to help better understand the compositional controls on fault gouge seal potential. The model is populated with a random assemblage of four fault rock components: shale smears, shaly gouge, cataclastic gouge and low-strain host-rock lenses. Harmonic averaging of permeability and arithmetic averaging of Vshale are then used to upscale the properties, and to propose a simple permeability–Vshale model for fault rocks. Practical application of the model is discussed by developing an empirical link between standard well-log data and associated fault rock effective permeability. This new approach has the potential to offer a simple well-log-based fault seal model. The utility of the model is demonstrated with a case study, comparing the results to those generated using other published techniques.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

Culture and the plasticity of perception

2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann
Keyword(s):  
Cultural Context ◽  
Sensory Experience ◽  
Cultural Learning ◽  
The World

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.

Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic
Keyword(s):  
Temporal Reasoning ◽  
Higher Order ◽  
Important Case ◽  
Human Cognition ◽  
Relational Reasoning ◽  
Dual Systems ◽  
First Order ◽  
Reasoning System ◽  
Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

Sociocultural memory development research drives new directions in gadgetry science

2019 ◽  
Vol 42 ◽  
Author(s):  
Penny Van Bergen ◽  
John Sutton
Keyword(s):  
Episodic Memory ◽  
Autobiographical Memory ◽  
Developmental Psychology ◽  
Cross Cultural ◽  
Memory Development ◽  
Development Research ◽  
Cultural Research ◽  
New Directions ◽  
Cross Cultural Research

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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