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Geotechnical soils mapping for construction purposes in Central Saudi Arabia
Published in P.G. Fookes, R.H.G. Parry, Engineering Characteristics of Arid Soils, 2020
J.S. Griffiths, P.G. Fookes, A.D. Hardingham, R.D. Barsby
Rockhead was close to the surface through the centre of the site and along the northern and western boundaries. The central tableland (Figure 1) was composed of Neogene arenaceous siltstones and argillaceous sandstones (although not proven to depth). Because this was a relatively young sedimentary rock it was deemed unlikely to possess the qualities necessary to make a good construction material. It would be suitable, however, as a rock fill (possibly select fill and sub-base). The northern part of the site was underlain by Cretaceous siltstones and sandstones. These older rocks displayed a weathering profile over three metres deep and had limited potential for use as construction materials. The Lower Cretaceous formation that formed an outcrop in the western margin of the project area was composed of moderately strong calcilutite and calcisiltite interbedded with anhydrite/gypsum rich residual soils. Particular beds within the sequence may have been be suitable as a source of crushed aggregate but processing the material to remove the salts would have been necessary. Jurassic rocks were found in the south west corner of the site and appeared to be mainly strong crystalline limestones. These were likely to be impregnated with anhydrite or gypsum close to rock head, but at depth may have provided a good supply of concrete aggregate, sub-base and also a good supply of large and small rock armour.
Dubai Strategic Sewerage Tunnel – challenges to infrastructure at unprecedented depths in the region
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2020
D. Brancato, A. Ayoubian, M. Joye, G. Monks, F.A. Al Awadhi, J. Tharamapalan
Based on the finalized tunnel alignments and by considering the available geotechnical data, the majority of the main tunnel alignment will cross the Barzaman formation. Typical rock core photographs of Barzaman Siltstone/Calcisiltite (left) and Conglomerate (right) are shown in Figure 4. However, the shallower sections of the Deira tunnel north alignment will encounter the Ghayathi formation. A typical rock core photograph of Ghayathi Sandstone is shown in Figure 5 The tunneling operations, along the deepest sections of Bur Dubai tunnels, at the area of Jebel Ali treatment plant, will cross the top layers of Fars formation (mudstone units).
Dubai Strategic Sewerage Tunnel – challenges to infrastructure at unprecedented depths in the region
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2019
D. Brancato, A. Ayoubian, M. Joye, G. Monks, F.A. Al Awadhi, J. Tharamapalan
Based on the finalized tunnel alignments and by considering the available geotechnical data, the majority of the main tunnel alignment will cross the Barzaman formation. Typical rock core photographs of Barzaman Siltstone/Calcisiltite (left) and Conglomerate (right) are shown in Figure 4. However, the shallower sections of the Deira tunnel north alignment will encounter the Ghayathi formation. A typical rock core photograph of Ghayathi Sandstone is shown in Figure 5 The tunneling operations, along the deepest sections of Bur Dubai tunnels, at the area of Jebel Ali treatment plant, will cross the top layers of Fars formation (mudstone units).
Sedimentary characteristics, formation mechanisms and geological significance of the Shiniulan Formation reefs (lower Silurian) in the Upper Yangtze Platform
Published in Australian Journal of Earth Sciences, 2019
P. Wang, X. F. Tan, H. Chen, J. Wang, L. Luo, H. Kuang, T. Ran, M. Liang, W Jiang
The Shiniulan Formation comprises four members. The lower member is composed of nodular limestone, grey to dark grey argillaceous limestone with brown calcareous silty mudstone, and a small amount of fossil traces. The base of the Shiniulan Formation, which inherited shallow shelf facies of the underlying Longmaxi Formation, represents a relatively quiet-water environment (Figures 2 and 3a). The second member contains yellow-grey calcisiltite, light-grey bioclastic limestone, with a small amount of silt-argillaceous limestone and fossils, such as bivalves, stromatoporoids, tabulate corals, cephalopods with worms on the bedding surface, representing a relatively high-energy depositional environment (Figure 3b, c). The third member includes grey-black reef limestone, grey to light-grey bioclastic limestone and bio-limestone, with a large number of corals (mainly Favosites and Halysites), stromatoporoids, gastropods and bivalves; the lower part outcrops as fuchsia limestone gravel with a some pelitic and silty stripe. The upper member comprises grey gravelly limestone and bioclastic limestone with some pelitic stripe, small-scale oblique bedding and locally low-angle cross-bedding, representing a relatively low-energy sedimentary environment (Figure 3d). The depositional environment of the Shiniulan Formation, in general, is a turbulent water environment, which is probably related to the sea-level changes, turbulence of water, agitation of terrigenous debris and biological activities of plankton and benthic organisms.
Predicting the pile static load test using backpropagation neural network and generalized regression neural network – a comparative study
Published in International Journal of Geotechnical Engineering, 2021
In these conditions, a thick salt crust can build and it might affect the pile’s performance. These deposits are common in the urban areas of UAE desert coastal regions and particularly extensive around this coastline. Beneath the first layers of sand and silt, other soil and rock materials exist. The Sand and Silt deposits cover interbedded sandstones, conglomerates, calcisiltite, limestone, and siltstones; clay deposits may also be encountered. Figure 2 shows a general subsurface profile commonly observed in the three cities.
Multi-scale approach to analyse the evolution of soft rock coastal cliffs and role of controlling factors: a case study in South-Eastern Italy
Published in Geomatics, Natural Hazards and Risk, 2021
Piernicola Lollino, Rossella Pagliarulo, Rosamaria Trizzino, Francesca Santaloia, Luca Pisano, Veronica Zumpano, Michele Perrotti, Nunzio Luciano Fazio
A different recession rate can be even observed through the whole cliff height, between the different calcarenite facies levels. A stronger enhancement of erosion is observed for the middle calcisiltite layer with respect to the upper and lower calcarenite layers. In order to investigate the influence of the differential weakening process of the two facies on the cliff stability a two-dimensional finite element model has been developed.