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Study on characteristics of the conglomerate reservoir in Shahezi Formation of XJWZ
Published in Ahmad Safuan Bin A Rashid, Junwen Zhang, Advances in Mineral Resources, Geotechnology and Geological Exploration, 2023
Shahezi Formation develops during the strong fracture period, which is affected by the XX fault of the main control fault, and the material source mainly comes from the east-west short axis direction. The parent rock component is from volcanic rocks, including tuff, rhyolite, rough rock, andesite, and early sedimentary conglomerates, breccia, and metamorphic rocks. Due to the large change in structural activity and the small width of the short axis, the rapid unloading of debris material results in poor sorting and grinding circle, different gravel sizes, particle support or matrix support, and angular gravel. The sandstone type is mainly feldspar rock chip sandstone, followed by rock chip sandstone, and rock chip feldspar sandstone, which reflects the characteristics of fast sedimentation speed, strong handling capacity, rapid hydrodynamic change, and close lithology in the study area.
Effect of confining pressure and frequency on ballast breakage
Published in Buddhima Indraratna, Trung Ngo, Ballast Railroad Design: SMART-UOW Approach, 2018
Buddhima Indraratna, Trung Ngo
The main factors that affect ballast degradation can be grouped into three categories: (i) properties related to the characteristics of the parent rock (e.g. hardness, specific gravity, toughness, weathering, mineralogical composition, internal bonding and grain texture); (ii) physical properties related to individual particles (e.g. soundness, durability, particle shape, size, angularity and surface smoothness); and (iii) factors associated with the assembly of particles and loading conditions (e.g. confining pressure, initial density or porosity, thickness of ballast layer, ballast gradation, the presence of water or ballast moisture content, and a cyclic loading pattern including load amplitude and frequency). While the properties of individual grains of ballast such as size, shape and angularity govern its degradation under traffic loading, deformation is also influenced by the magnitude of wheel (or axle) load, frequency (equivalent to train speed) and the number of load cycles (Sun et al. 2014a, 2016). This chapter presents the influences of confining pressure and frequencies on the degradation of railway ballast.
Mineralogy and microfabric of unsaturated residual soil
Published in H. Rahardjo, D.G. Toll, E.C. Leong, Unsaturated Soils for Asia, 2020
K.K. Aung, H. Rahardjo, D.G. Toll, E.C. Leong
Residual soils are formed by the weathering of different parent rocks. Most of the residual soils around the world are normally found in tropical regions and are usually unsaturated in nature. The degree of weathering varies with depth from fresh rock to a completely weathered condition and finally residual soils are formed. This varied degree of weathering makes the residual soils different in terms of mineralogy and soil fabric from their parent rocks. During the weathering process, parent rock minerals are decomposed and soil structures are disintegrated. In this paper, the mineralogy and soil microfabric of residual soils from the Bukit Timah granitic formation in Singapore are described.
Geotechnical investigation and statistical relationship of subsoil properties derived from two parent rock types in Southwestern Nigeria
Published in Cogent Engineering, 2022
Temitayo Olamide Ale, Tolulope Henry Ogunribido, Modupe Anne Kolawole, Taiwo Ayomide Ale
The type of soil formed is a function of the parent rock type, mineral constituents and the peculiarity of the region. Akintorinwa and Oluwole (2018) compared the properties of subsoil underlain by different parent rocks and found out that soil derived from Charnockite, Migmatite and granite rock have higher shear strength than the low cohesive nature of quartzite. A Nigerian good soil material must meet and exceed expectation/specification of tropical environment (Ale, 2022). Quality attention must be given to combinations of factors responsible for failure of these roads in order to achieve sustainable development in developing countries. The major road that passes through Erusu Akoko is a federal road of about 3.5 kilometers which links the northern part of Nigeria with the southern part. Erusu Akoko road is underlain by two major rock types of granite gneiss and grey gneiss. On this road are visible cracks, potholes, bulges and depression caused majorly by heavy duty trucks plying this road. This study is aimed at using geotechnical properties and statistical relationship between geotechnical parameters to evaluate the performance of subsoil derived two different rock types for pre- and post-engineering construction planning and design of roads. This analysis will also help to establish which of the two rock types’ derived soil has better geotechnical properties. The obtained results will be compared with international and national standards and recommendation of suitable materials (In-situ or Ex-situ).
Mineralogical and geochemical characterisation of kaolin deposit from Debre Tabor area northwestern, Ethiopia
Published in Applied Earth Science, 2021
Alemu Mesele, Teklay Gidey, Tilahun Weldemaryam, Wuletaw Mulualem, Tamrat Mekuria, Yahya Ali, Gizachew Mulugeta, Betelhem Tesfaye, Mulgeta Brihan
Most of the trace elements are enriched in clay minerals because the deposit has the capacity of scavenging the ions (Meshram and Randive 2011; Gu et al. 2013). The multi-elemental spider diagram represents the distribution of trace elements in the kaolin deposit and shows negative Sr, Ba, and Ti (Figure 8(b)). The negative Sr anomaly is related to the dissolution of calcium-rich primary mineral; Ba is a mobile element, while Ti is immobile, but this anomaly indicates the lack of Ti bearing minerals in the parent rock (Mordberg and Spratt 1998). The chondrite normalised REE pattern of the Debre Tabor kaolin deposit (Figure 8(a)) shows the distribution of REEs during the mineralogical reaction. Weathering of the parent rock minerals causes mobilisation of elements and fractionation of LREEs and HREEs (Karadağ et al. 2009; Meshram and Randive 2011; Olusola et al. 2014; Sadaf et al. 2015). The kaolin and parent rock samples show a slightly negative Eu anomaly and this can be traced to the presence of feldspar in all the samples (Da Costa and Moraes 1998). Besides, REEs are released from primary minerals and adsorbed on the surface of clay minerals (Karadağ et al. 2009; Akinyemi et al. 2014). Therefore, clay minerals are an important factor that affects the leaching degree of rare earth elements (Condie 1991).
Development of integrated railway ballast quality index
Published in International Journal of Pavement Engineering, 2021
J. Sadeghi, M. Emad Motieyan, J. Ali Zakeri
For the development of the physical index, five parameters (tests) were considered as the sub-criteria in the model, namely, gradation, fine mass amount, particle shape, specific gravity, and bulk unit weight. The mechanical index was developed in a similar manner. The type of parent rock (mineralogy test), dry abrasion, wet attrition and abrasion and crushing resistance were taken into consideration. Environmental index (soundness/weather resistance) was developed based on water absorption, thaw and freezing cycles as well as sodium/magnesium sulphate.