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Minerals and rocks
Published in A.C. McLean, C. D. Gribble, Geology for Civil Engineers, 2017
The occurrence of sedimentary structures indicates some variation in composition or texture of sedimentary rock layers in response to changes in the environmental conditions in which the particular sediment was laid down. Two of the most common sedimentary structures, graded bedding and cross.bedding, are associated with sorting.
Basin Analysis: A Synthesis
Published in Supriya Sengupta, Introduction to Sedimentology, 2017
Subtle changes within the sedimentary structures may also be used as indicators of variation in physical condition within a depositional environment. Cross-strata sets, for example, are sometimes interrupted by sloping surfaces called reactivation surfaces (Fig. 9.3B). These may be caused by changes in flow stages (a lowering of water level followed by rising) of the depositing medium. In the case of reversal of flow direction due to tidal effect, the cross-strata above and below the reactivation surface may dip in opposite directions, giving the impression of herringbone structures (Fig. 9.3A).
Mechanics of biofilm-coated sediment transport
Published in Silke Wieprecht, Stefan Haun, Karolin Weber, Markus Noack, Kristina Terheiden, River Sedimentation, 2016
H.W. Fang, H.M. Zhao, W. Cheng, M. Fazeli, Y.S. Chen, Q.Q. Shang, G.J. He, L. Huang
Sedimentary systems are governed by a series of dynamic processes, such as erosion, transport, deposition and deformation, which create numerous sedimentary structures, including ripple marks of different morphologies and dimensions, current laminations, ball and pillow structures, convolute bedding, bubble sand etc (Noffke N & Paterson D, 2008). Physical sediment dynamics, usually accompanied by the associated release and relocation of contaminants in aquatic environment, are important processes which must be considered in the integrated management of rivers and coastal areas (Paterson et al. 1999, Foerstner et al. 2004). The possibility of sediment erosion occurrence and the degree in terms of erosion rate and depth are determined by the interplays of two kinds of forces imposed on sediments with different effects, i.e., the hydrodynamic forcing (e.g. river flow, tidal flow, density driven circulation and wind waves) and the resisting forces (e.g. sediment cohesion, gravity, biogenic stabilization) (Gerbersdorf et al. 2008).
Soft computational approach on the thermoelastic assessment of the sandwich beams with transversely functionally graded composite concrete face-sheets as an advanced building material
Published in Mechanics of Advanced Materials and Structures, 2023
Dandan Li, Peng Wang, Nadia Sarhan, Mohamed Sharaf
Permeability prediction models play a crucial role in assessing the behavior of clay soil foundations [63]. Chen et al. [64] proposed a modified Kozeny-Carman model to improve the accuracy of permeability predictions for building foundations. Zhan et al. [65] reviewed the application of deep learning in subsurface sedimentary structure identification, highlighting its potential in enhancing geological understanding. Xu et al. [66] proposed an upscaling approach to predict mine water inflow from roof sandstone aquifers. The detection of interfacial debonding in concrete-filled steel tube (CFST) structures is critical for ensuring their structural integrity [67,68]. Han et al. [69] conducted experimental studies to evaluate the resistance of the matrix and interfacial transition zone to chloride ion penetration. Tunneling in coarse-grained soils poses challenges in urban areas, particularly regarding surface settlement [70]. Liu et al. [71] conducted field tests and finite element analysis to investigate the role of asymmetric tail-grouting in controlling surface settlement during tunnel boring machine (TBM) excavation. Stochastic processes are employed to model safety risks in the construction industry. Zhang et al. [72] analyzed stochastic processes and their application in modeling safety risks, contributing to risk management strategies. Liu et al. [73] investigated the development of cracks and damage in shield tunnel linings under seismic loading conditions.
Paleo-environment and provenance in a lacustrine shallow-water delta-meandering river sedimentary system: insights from the Middle–Upper Jurassic formations of the Fukang Sag of Junggar Basin, NW China
Published in Australian Journal of Earth Sciences, 2019
L. Luo, X. Gao, X. Tan, J. Gluyas, J. Wang, X. Kong, J. Huang, H. Shao, F. Qu
Lithofacies of facies association B include green-grey–grey siltstone, fine sandstone (several metres to tens of metres in scale) and mudstone with a relatively low sand–strata ratio (0.2–0.5) (Figure 12). The sedimentary structures include parallel bedding, current bedding, cross-bedding and basal erosion scouring structures, wave ripples, sphenoid cross-bedding, lenticular bedding and slump structures. The cumulative particle size probability curve of the main sand body, which has a relatively steep slope, comprise two sections representing the more abundant bouncing component and the more minor suspension-transport component (Figure 12). The GR curve of the main sand body generally shows bell-shaped or box- and funnel-shaped middle amplitude variations. The GR curve of the interbedded siltstones and mudstones shows serrated low-amplitude variations (Figure 12).
Zebra rock and other Ediacaran paleosols from Western Australia
Published in Australian Journal of Earth Sciences, 2021
This is a facies of purple-red siltstone finely interbedded with grey-green siltstone beds. Individual beds are mostly 1–4 mm thick. Some units 15–20 cm thick are more massive with grey-green mottles on the top, but most of the bed is red (Figure 5b, c), and others contain gypsum rosettes (Figure 4c, d). Horizontal planar and wavy bedding are the main sedimentary structures, but there are also straight-crested ripples, shallow hexagonal mud cracks and thin claystone breccias. Mud cracks from RG facies have been illustrated by Lan and Chen (2013).