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Stabilisation of Soils
Published in P.A. Konovalov, Bases and Foundations of Buildings under Reconstruction, 2020
Silicification is based on the application of silicate solutions or their derivatives which, when combined with a coagulant, form a silicic acid gel that cements the soil particles, especially in collapsible soil. In the bichemical grouting method two chemicals, sodium silicate and the coagulant calcium chloride, are successively pumped through a steel injector comprising steel tubes of 19 to 38 mm diameter pushed into the soil to the required depth. The silicic acid gel that forms consequent to mixing, imparts a compressive strength of 1.5–5.0 MPa as well as impermeability to the soil.
Rock characterization
Published in Dean Brox, Practical Guide to Rock Tunneling, 2017
Rock alteration can increase the strength of rock due to silicification with the introduction of silica and can decrease the strength of rock due to the replacement of hard minerals with soft/weak minerals including sericite, chlorite, and clay minerals.
Early Cretaceous glacial environment and paleosurface evolution within the Mount Painter Inlier, northern Flinders Ranges, South Australia
Published in Australian Journal of Earth Sciences, 2020
S. B. Hore, S. M. Hill, N. F. Alley
The litholog (Figure 8) of our Reference Section ‘tillite A’ highlights the correlation of this ‘tillite A’ exposure in part with the Trinity Well Sandstone (Alley et al., 2020) and in part with the Sheehan Tillite Member; we interpret such parts as glacial and pro-glacial facies, respectively. These sediments represent a transition zone between the periglacial, pro-glacial and glacial sediments found overlying the basement within the ranges (discussed below) and the glacigene sediments deposited during the Sheehan Glacial Event, found locally within the thick Eromanga Basin (Figure 5) (Alley et al., 2020). The exposure (‘tillite A’) of basin sediments, deposited on basement rocks, is currently in a relatively elevated position owing to the effects of neotectonic activity along the Paralana Fault Zone. Silicification has resulted in strong induration relative to that of surrounding rocks and has contributed in their present state of preservation. The associated glacigene deposits within the Eromanga Basin (Figure 5) are now represented by limited exposures visible along the rangefront to the south of the PHS area and to the north within and beyond the Four Mile area (Alley et al., 2020; Callen, 1974; Coats et al.,1969; Hore & Hill, 2009a), and is also recorded by drill-hole intercepts (Alley et al., 2020; Heathgate Resources Pty Ltd, 2016).
Mesoproterozoic rift sedimentation, fluid events and uranium prospectivity in the Cariewerloo Basin, Gawler Craton, South Australia
Published in Australian Journal of Earth Sciences, 2018
S. R. Beyer, K. Kyser, P. A. Polito, G. L. Fraser
The upper Pandurra Formation contains pervasive hematite and quartz cementation in portions of the study area. The hematite is commonly present as liesegang banding and can be conspicuously crystalline, both of which distinguish it from Fe oxides lower in the Pandurra Formation. Locally intense silicification is manifest as quartz cement occluding porosity. Liesegang-banded hematite occurs as deep as 380 m, and silicification extends to nearly 200 m deep around the Pernatty Lagoon (Cowley, 1991; Figure 1). The occurrence of these minerals is consistent with silcretes and lateritic weathering that occurred prior to 827 Ma considering that silicified Pandurra clasts are contained in the Backy Point Formation (Cowley, 1991).