scholarly journals Evaluation of Lithology Variations in Layered Red Beds with Depth: An Example of the Yellow River Guxian Dam, NW China

Lithosphere ◽  
2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Qing-Bo Li ◽  
Jun-Zhi Wang ◽  
Gui-Jun Wang ◽  
Qing-Liang Liu ◽  
Chang-Bin Yan
Keyword(s):  
Rock Mass ◽  
Hard Rock ◽  
Yellow River ◽  
Shear Zones ◽  
The Yellow River ◽  
Red Beds ◽  
Hard Rocks ◽  
Rock Types ◽  
Borehole Logs ◽  
Argillaceous Siltstone

Abstract Lithology variations, which are recognized as rock type differences, significantly affect the physical properties of rock masses in red beds. In this paper, we introduce a statistical method for quantitatively evaluating the degree of lithology variations in layered red beds with depth. The core of this method is to use borehole logs as random variables for statistical analysis to calculate the percentage of a specified lithology at a given elevation, which involves seven steps of attitude calculation, reference point selection, distance calculation, elevation modification, data discretization, data statistics, and curve plotting. The Yellow River Guxian Dam is chosen as a field case study. We classify rock types of feldspar sandstone, fine sandstone, and conglomerate into hard rocks and that rock types of calcareous siltstone, argillaceous siltstone, and mudstone into soft rocks. Borehole logs recorded during the geological investigation are used to plot the percentage curve of hard rocks. We find that the degree of lithology variations for each lithology group differs greatly, the general behaviors of lithology variations on two sides of the Guxian Dam riverbed are quite similar but still with some differences, and that some thick lithology groups can be finely divided into several subgroups. On the basis of the hard rock percentage curve, we introduce a lithology variation index to quantitatively characterize the degree of lithology variations, which can be used as an important index to supplement the traditional methods when performing rock mass classifications in red beds. We also plot the trilithology percentage curve of sandstone, calcareous siltstone, and argillaceous siltstone, which serves for the determination of physical parameters of the dam foundation rock mass, the identification of the potential shear sliding surface, and the search for an impervious grouting bottom. Moreover, we find that the crest and trough, which are local high and low points in the hard rock percentage curve, can be used to show some characteristics of shear zones. The locations of shear zones are well represented in the form of troughs and that the development of shear zones has a good linear relationship with the hard rock percentage of the corresponding crest. The method proposed in this paper can be promoted and applied in similar projects or studies.

scholarly journals Rockslides on limestone cliffs with subhorizontal bedding in the southwestern calcareous area of China

2014 ◽  
Vol 14 (9) ◽  
pp. 2627-2635 ◽  
Author(s):  
Z. Feng ◽  
B. Li ◽  
Y. P. Yin ◽  
K. He
Keyword(s):  
Numerical Modeling ◽  
Rock Mass ◽  
Hard Rock ◽  
Compression Fracture ◽  
Field Observations ◽  
Mountainous Areas ◽  
Hard Rocks ◽  
Rupture Plane ◽  
Rock Collapse ◽  
Cliff Retreat

Abstract. Calcareous mountainous areas are highly prone to geohazards, and rockslides play an important role in cliff retreat. This study presents three examples of failures of limestone cliffs with subhorizontal bedding in the southwestern calcareous area of China. Field observations and numerical modeling of Yudong Escarpment, Zengzi Cliff, and Wangxia Cliff showed that pre-existing vertical joints passing through thick limestone and the alternation of competent and incompetent layers are the most significant features for rockslides. A "hard-on-soft" cliff made of hard rocks superimposed on soft rocks is prone to rock slump, characterized by shearing through the underlying weak strata along a curved surface and backward tilting. When a slope contains weak interlayers rather than a soft basal, a rock collapse could occur from the compression fracture and tensile split of the rock mass near the interfaces. A rockslide might shear through a hard rock mass if no discontinuities are exposed in the cliff slope, and sliding may occur along a moderately inclined rupture plane. The "toe breakout" mechanism mainly depends on the strength characteristics of the rock mass.

scholarly journals Rockslides on limestone cliffs with sub-horizontal bedding in the southwestern calcareous area, China

2014 ◽  
Vol 2 (6) ◽  
pp. 4299-4330
Author(s):  
Z. Feng ◽  
B. Li ◽  
Y. P. Yin ◽  
K. He
Keyword(s):  
Rock Mass ◽  
Hard Rock ◽  
Compression Fracture ◽  
Field Observations ◽  
Rock Slide ◽  
Mountainous Areas ◽  
Hard Rocks ◽  
Rupture Plane ◽  
Rock Collapse ◽  
Cliff Retreat

Abstract. Calcareous mountainous areas are highly prone to geohazards, and rockslides play an important role in cliff retreat. This study presents three examples of failures of limestone cliffs with sub-horizontal bedding in the southwestern calcareous area of China. Field observations and numerical modeling of Yudong Escarpment, Zengzi Cliff, and Wangxia Cliff showed that pre-existing vertical joints passing through thick limestone and the alternation of competent and incompetent layers are the most significant features for rockslides. A "hard on soft" cliff made of hard rocks superimposed of soft rocks is prone to rock slump, characterized by shearing through the underlying weak strata along a curved surface and backward tilting. When a slope contains weak interlayers rather than a soft basal layers, a rock collapse could occur from the compression fracture and tensile split of the rock mass near the interfaces. A rock slide might shear through a hard rock mass if no discontinuities are exposed in the cliff slope, and sliding may occur along a moderately inclined rupture plane. The "toe breakout" mechanism mainly depends on the strength characteristics of the rock mass.

scholarly journals Substantiating a technique to process hard rock involving extraction of valuable components and use of wastes to form mesorelief

2019 ◽  
Vol 109 ◽  
pp. 00003
Author(s):  
Kateryna Babii ◽  
Oleksandr Ikol ◽  
Yevhenii Malieiev
Keyword(s):  
Rock Mass ◽  
Hard Rock ◽  
Industrial Product ◽  
Power Dependence ◽  
Landscape Restoration ◽  
Hard Rocks ◽  
Mineral Losses ◽  
Scientific Value ◽  
Practical Implications

A technique to process rock mass from hard-rock technogenic media has been developed; it is aimed at recovery of mineral losses, restoration of the environment at the territory of mining enterprises by means of rock mass extraction, its processing and redistribution for the purposes of land recultivation and landscape restoration. Classification of dry ore-containing hard rocks of dumps has been developed; that has made it possible to improve technological scheme of the processing of rock mass from technogenic media, emphasize its variants of use, and specify the required facilities and their productivity. Scientific value of the paper is in determining the effect of changes in the losses in pre-processing dry wastes upon the yield of industrial product and wastes; the effect has demonstrated that the yield of industrial product is in polynomial dependence upon the pre-processing losses while yield of tailings is in the power dependence. Practical implications of the paper are in the fact that the proposed method helps form mesorelief with the properties close to the natural one. The method involves restoration of the initial landscape with the help of opening hard rocks followed, completed by laying water-bearing and potentially fertile layers.

scholarly journals Classification of Red-Bed Rock Mass Structures and Slope Failure Modes in South China

Geosciences ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 273 ◽  
Author(s):  
Cuiying Zhou ◽  
Xu Yang ◽  
Yanhao Liang ◽  
Zichun Du ◽  
Zhen Liu ◽  
...  
Keyword(s):  
Rock Mass ◽  
South China ◽  
Slope Failure ◽  
Failure Modes ◽  
Hard Rock ◽  
Soft Rock ◽  
Red Beds ◽  
Rock Falls ◽  
Geological Formation ◽  
Red Bed

Red beds are Meso–Cenozoic continental sedimentary strata that are mainly composed of gravel stone, sandstone, siltstone, mudstone, and shale and occasionally have interlayers of limestone, halite, and gypsum. As a typical rock mass, red beds are widely distributed throughout South China. In a typical tropical and subtropical continental environment, red beds are the product of multiple sedimentary cycles, which have resulted in complicated rock mass structures that play an important role in rock mass stability. It is thus of great significance to investigate the influence of different rock mass structures on the stability of red-bed slopes. In this paper, the geological formation history of red beds in South China is described. The main features of red-bed rock mass slopes in South China are discussed. The main combinations of inner geomechanical structures comprise: (1) mega-thick soft rock structures; (2) mega-thick hard rock structures; (3) thick hard rock structures with weak intercalation; and (4) soft–hard interbedded structures. In addition, the features of slope failure are analyzed, and four common failure modes are identified from the statistical data: (a) weathering spalling and scouring; (b) rock falls; (c) landslides; and (d) tensile dumping.

Primary Engineering Geological for Shuibuya Underground Power Station and their Treatment

2011 ◽  
Vol 368-373 ◽  
pp. 608-612
Author(s):  
Jing Hua Liu ◽  
Jian Jun Zhou
Keyword(s):  
Rock Mass ◽  
Hard Rock ◽  
Shear Zones ◽  
Left Bank ◽  
Power Station ◽  
Diversion Tunnel ◽  
Underground Powerhouse ◽  
Power House ◽  
The Right ◽  
Installed Capacity

The Shuibuya hydropower station is located in Badong County in the middle reach of Qingjiang River. It is the first cascaded project in Qingjiang mainstream. The Project consists of a concrete faced rock fill dam (CFRD), underground power house, chute spillway on the left bank, and the sluice tunnel on the right bank. The dam is 233m high, which is the highest of its kind in the world at present. The installed capacity and annual output of Shuibuya Power Plant are 4×460MW and 3.92 GWh respectively. The rock mass of foundation of Shuibuya project is a type of stratified sedimentation rock mass is composed of interbedded stratum by weak layers and hard layers. To solve engineering geological problem is difficult and challenging. For example, the intake slope of Shuibuya hydropower diversion tunnel was a landslide, and diversion tunnel outlet is located at the toe of Maya slope with 360m high, rock mass of the underground powerhouse caverns are soft and hard rock inter-layered, with multi-structural planes, multi-shear zones, and the lithology of rock is highly krast. Some researchs and geological treatments were performed during the geological exploitation and construction, which is fundamental and primary.

GEOMORPHOLOGICAL CHARACTERISTICS OF A TRANSECT FROM THE YELLOW RIVER TO THE IRON PAGODA IN KAIFENG CITY, CHINA

2018 ◽  
Vol 14 (1) ◽  
pp. 245-254 ◽  
Author(s):  
Yang LI ◽  
◽  
Zhixiang XIE ◽  
Fen QIN ◽  
Yaochen QIN ◽  
...  
Keyword(s):  
Yellow River ◽  
The Yellow River ◽  
Kaifeng City
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