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Experience on a standard penetration test
Published in A. Verruijt, F.L. Beringen, E.H. De Leeuw, Penetration Testing, 2021
At present, some departments in China are now making careful study of further application and improving of technology of S.P.T., such as: – Problem on number of blows effecting foundation in loose sand layer,– Problem on softening of uneven distributed weathered rock stratification (eluvium) under water, inspected by means of S.P.T.;– Problem on automatic equipment needed for S.P.T. and combination of automatic equipment and knock-boring misering, also problem on revision of length of the boring rod;– Experience on application of special foundation soil and regional soil.
Seismic velocity fields and landslide conditions
Published in Jan Rybář, Josef Stemberk, Peter Wagner, Landslides, 2018
The velocity field divides the investigated rock massif into three blocks. The undeteriorated schists and their weathering products are found in Block I. These are formed of loams and below them there is an eluvium and a soft rock massif. The total thickness of these beds is c. 25 meters. On the other hand the most deteriorated rock massif is in Block III. The more gradual velocity increase with the depth and bigger velocity changes in the horizontal direction can be seen quite clearly on the velocity contour lines. The base of the third velocity bed (according to the crossover distance method) is not found as far as the depth of 40 meters in this block. This suggestion, as well as the field visual inspection, can allow us to express the presumption that the base of the deteriorated rock massif caused by the slope movement exists in the depth over 50 meters.
Study on the design and protection of a subgrade side slope in the distribution area of loose accumulation bodies
Published in Xiaoling Jia, Feng Wu, Electromechanical Control Technology and Transportation, 2017
For the soil side slope of eluvium layer, because of the condition of its formation and engineering nature, the general design principle for the zone that is vulnerable to engineering geological disaster is to avoid excavation of such side slope as much as possible. If such zone has to be excavated because of restriction by criteria of the route, the excavation shall be reduced as much as possible. The general design principle is as follows:
A comparison among fuzzy multi-criteria decision making, bivariate, multivariate and machine learning models in landslide susceptibility mapping
Published in Geomatics, Natural Hazards and Risk, 2021
Quoc Bao Pham, Yacine Achour, Sk Ajim Ali, Farhana Parvin, Matej Vojtek, Jana Vojteková, Nadhir Al-Ansari, A. L. Achu, Romulus Costache, Khaled Mohamed Khedher, Duong Tran Anh
In study area, the landslide inventory data consisted of slow-moving, which were caused by the change in the hydrologic-geologic processes in the area of the landslide, especially, an increase in levels of groundwater. The share of deep-seated landslides out of all landslide locations was 16.1%. On the other hand, shallow-rapid landslides, which were caused predominantly by intense rainfall, but also lateral/vertical erosion or their combination, accounted for 83.9% of all landslide locations. In this cases, sudden saturation loosened the soil and triggered the landslide, i.e. gravity overtook the hillside and the muddy soil mass broke loose. In addition, 93.3% of landslides occurred on Paleogene rocks, 3.4% on Cretaceous rocks, and 3.3% on Jurassic rocks. The geological structure of 67.8% of landslides was represented by mixed and talus soils/eluvium whilst the geology of 32.2% of landslides was created by clayey and fragmentary unconsolidated rocks (consistent and frictional soils).
A complex slide-buckling-toppling failure of under-dip soft rock slopes
Published in European Journal of Environmental and Civil Engineering, 2020
The under-dip slope is located on the perimeter of the west railway station under construction in Chongqing city, China, and at the western wing of the Zhenxichang syncline. The cutting slope has a maximum height of 70 m and is mainly comprised of moderately weathered shale with bedding planes presenting an orientation of 102°/68° (dip direction/dip angle) and a spacing varying from 0.1 m to 0.4 m (Figure 1). Figure 2 shows some characteristics of the studied landslide area and the geological profile at the cross-section A-A’ (Figure 1) based on three drill holes is displayed in Figure 3a. The shale belongs to typical soft and fragile sedimentary rock, which is very weak in resistance to weathering. By long-term influence of weathering, there is a layer of eluvium on the shallow with a varying depth ranging from 1 to 4 m (Figure 3a).
Ti–Zr placers and weathering crusts of the Karaotkel and Satpaev deposits, Kazakhstan
Published in Applied Earth Science, 2019
Yertlek Suiekpayev, Yerzhan Sapargaliyev, Mikhail Kravchenko, Alla Dolgopolova, Reimar Seltmann, Askhat Azelhanov
The following zones are identified in the weathering crust profiles in the study area (from the top down): (1) a kaolin clay zone represented by bleached clay eluvium that does not retain any protolith structure; (2) a hydro-mica to clay eluvium zone consisting of clay products of generated during chemical decomposition while retaining the structure of the parent rocks; (3) zone of disintegration – a zone of tectonised eluvium consisting of weathered, highly fissured rocks bleached as a result of the partial removal of alkalis and the hydration of micas. The ore-bearing units are clays of the Aral Formation that are divided into lower and upper members separated by a boundary in the form of an inter-formation break in the deposition of clay units and the erosion associated with the development of weathering crusts.