scholarly journals The Influences of Local Glacitectonic Disturbance on Overconsolidated Clays for Upland Slope Stability Conditions: A Case Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10718
Author(s):  
Kamil Kiełbasiński ◽  
Paweł Dobak ◽  
Łukasz Kaczmarek ◽  
Sebastian Kowalczyk
Keyword(s):  
Slope Stability ◽  
Slip Surface ◽  
Geological Structure ◽  
Calculation Model ◽  
Stability Conditions ◽  
State Evaluation ◽  
Geological Conditions ◽  
Wide Range ◽  
Spatial Diversification ◽  
The Impact

Reliability of equilibrium state evaluation about settlement slopes in the context of natural and human-made hazards is a complex issue. The geological structure of the vicinity of the upland slope in the urban environment of Warsaw is characterised by a significant spatial diversification of the layers. This is especially due to the glacitectonics in the Mio-Pliocene clays, which are located shallowly under the sandy tills’ formations. With substantial variability in the clay roof surface, point recognition by drilling is often insufficient. The use of electrical resistivity imaging (ERI) in the quasi-3D variant provides accurate images of the real ground conditions, which is crucial in optimal geotechnical design. In forecasting the behaviour of the slope, it is necessary to quantify the impact of spatially differentiated systems of disturbed layers on changes in the safety factor (SF), which corresponds to the observed landslide activity of the Warsaw Slope. This study concerns numerous calculation model analyses of the optional clay position in the context of slope stability conditions. A wide range of soil properties variability was taken into account, resulting from both lithogenesis and subsequent processes disintegrating the original soil structure. Regarding the geological conditions of the slip surface, the use of classical computational methods and numerical modelling (FEM) was considered for comparative purposes. The results indicated that local changes in equilibrium conditions were affected by the different morphology of the clay roof surface of the slope and the alternation in strength characteristics on the slip surfaces. The findings of the study contribute to sustainable spatial planning of near-slope regions.

scholarly journals Selected components of geological structures and numerical modelling of slope stability

2019 ◽  
Vol 11 (1) ◽  
pp. 208-218 ◽  
Author(s):  
Łukasz D. Kaczmarek ◽  
Paweł Popielski
Keyword(s):  
Slope Stability ◽  
Numerical Modelling ◽  
Soil Layer ◽  
Friction Angle ◽  
Geological Structure ◽  
Soil Permeability ◽  
Structural Discontinuity ◽  
Geological Conditions ◽  
Shear Strength Reduction Method ◽  
The Impact

Abstract This paper presents the impact of selected essential aspects of geological structure on the state of slope stability as assessed by changes in the safety factor (SF). The engineering geological slope features that were analysed include: (i) changes in soil cohesion and internal friction angle, (ii) presence of a weak soil layer and its span, (iii) structural discontinuity (i.e. fault), (iv) soil permeability properties and water conditions (i.e. groundwater level, long and heavy rainfall). A certain scheme of slope stability calculations has been proposed for a case involving complex geological conditions. The numerical modelling of a hypothetic slope was performed using the shear strength reduction method based on the finite element method.

scholarly journals On evaluation of complex-structured coal deposits based on their typical geometric features

2021 ◽  
Vol 303 ◽  
pp. 01029
Author(s):  
Alexander Katsubin ◽  
Victor Martyanov ◽  
Milan Grohol
Keyword(s):  
Surface Mining ◽  
Geological Structure ◽  
Point Of View ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Operations ◽  
Coal Deposits ◽  
Geological Conditions ◽  
Wide Range ◽  
Large Length

Information about the geological structure of Kuznetsky coal basin (Kuzbass) allows us to note that coal deposits developed by open-cast method are characterized by complicated conditions and have the following features: large length of deposits at significant depths of occurrence; coal series bedding of different thicknesses (from 1 to 40 m); different dip angles (from 3 to 90º); a significant number of dip and direction disturbances; different thickness of unconsolidated quaternary sediments (from 5 to 40 m); a wide range of strength values of rocks. In addition, there is a thickness irregularity and frequent variability of elements of occurrence of coal seams within the boundaries of a quarry field both in length and depth of mining. From the point of view of open-pit mining, such deposits are complex-structured. The factors listed above have a decisive influence on the choice of technical means, the order of development and the possibility of carrying out surface mining operations. Therefore, there is a need for a systematization of mining and geological conditions for the development of coal deposits, the purpose of which is to ensure a process of evaluation of complex-structured coal deposits for the development of coal-bearing zones by various complexes of equipment.

scholarly journals ACTIVE, PASSIVE AND STABLE SHORES OF THE SEA OF AZOV

2021 ◽  
Vol 1 (6) ◽  
pp. 178-184
Author(s):  
A.E. Tsygankova ◽  
L.A. Bespalova ◽  
A.A. Magaeva ◽  
E.V. Bespalova ◽  
D.A. Podkolzina
Keyword(s):  
Geological Structure ◽  
Coastal Processes ◽  
Type I ◽  
Sea Of Azov ◽  
Natural Factor ◽  
The Sea Of Azov ◽  
Type Iv ◽  
Geological Conditions ◽  
Structure Height ◽  
The Impact

The purpose of this work is to comprehensively study the ecological and geological conditions and the results of monitoring studies of the coastal territories of the Taganrog Bay and the Sea of Azov to identify the degree of manifestation of dangerous coastal processes (DCP). The subject of the study is to assess the degree of manifestation of DCP under the influence of various natural factors, both constant in time (geological structure, height of the coastal cliff), and changing (dynamics of the level, waves, wind regime) and the impact of man-made causes. The performed factor analysis allows us to assert that the main natural factor of the intensification of DCP is the extreme surge levels (adverse end dangerous events: AE and DE). The types of shores are constant, but with different degrees of manifestation of DCP, they change significantly. As a result, according to these studies, maps were constructed for the average long-term (1980), intensive manifestation (2013–2014) and the period with a relatively calm manifestation of the intensity of DCP (2018–2020). According to the activity, the manifestations of DCP are divided into 4 types: type I – with a very high c (>4 m/year), type II – with a high (2–4 m/year), type III – with an average (1–2 m/year), type IV – with a weak rate (<1 m/year) of abrasions, which include subtypes of banks formed by exogenous processes (abrasive, abrasive-landslide, accumulative), indicating the conditions of their formation and the reasons for the isolation of the danger of coastal processes.

Analysis of Disaster Response During Landslide Disaster in Hakha, Chin State of Myanmar

2018 ◽  
Vol 13 (1) ◽  
pp. 99-115 ◽  
Author(s):  
May Myat Mon ◽  
Tun Naing ◽  
Muneyoshi Numada ◽  
Khin Than Yu ◽  
Kimiro Meguro ◽  
...  
Keyword(s):  
Slope Stability ◽  
Disaster Response ◽  
Mountainous Regions ◽  
Gis Tools ◽  
Technical Control ◽  
Geological Conditions ◽  
Management Procedures ◽  
Urban Safety ◽  
The Impact ◽  
New Location

Myanmar has experienced many types of geologic hazards such as earthquakes and landslides and to a lesser extent, subsidence. In recent years, landslides have been a major form natural disaster in Myanmar, especially in the country’s mountainous regions, such as Chin State. In geomorphological terms, Myanmar has two mountainous regions: namely the Western Ranges and the Eastern Highlands. Steep slopes, unstable geologic conditions, and heavy monsoon rains make these regions the most landslide-prone areas in Myanmar. The study area, Hakha City and its environs, is situated in Chin State, which occupies a part of the Western Ranges. Chin State suffers many landslide incidents each year. Human settlement has recently increased as a result of rapid population growth. Consequently, natural and man-made disasters are on the rise and affecting people more than before. The most devastating landslide on record in Myanmar occurred in July 2015 due to the impact of Cyclone Koman. After this landslide, some places of Hakha City resettled in new location. However, a detailed slope stability analysis and assessment of the new location have not yet been carried out. In addition, management procedures and systems for the relocation and resettlement process still need to be evaluated for the urban safety space. Existing research and papers focus mainly on the areas affected by the landslide rather than on the city’s new location based on geographic information system (GIS) tools. It is essential to study the potential risk of landslides in the new location properly, and identify an appropriate management system. Geological conditions including highly weathered and crushed rocks, heavy rainfall intensity, and poor drainage systems combine slope stability. Systematic management programs and technical control methods can mitigate the number and magnitude of future disasters.

scholarly journals Stability Calculation Method of Slope Reinforced by Prestressed Anchor in Process of Excavation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhong Li ◽  
Jia Wei ◽  
Jun Yang
Keyword(s):  
Slope Stability ◽  
Slip Surface ◽  
Calculation Model ◽  
Design Parameters ◽  
Search Model ◽  
Critical Slip Surface ◽  
Stability Calculation ◽  
Optimal Stability ◽  
Dynamic Search ◽  
Prestressed Anchor

This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tension of the whole process is also given out, through which the real-time analysis and checking of slope stability in the process of excavation can be realized. The calculation examples indicate that the slope stability is changed with the dynamic change of the design parameters of anchor and grillage beam. So it is relatively more accurate and reasonable by using dynamic search model to determine the critical slip surface of the slope reinforced by prestressed anchor and grillage beam. Through the relationships of each anchor layout and the slope height of various stages of excavation, and the optimal stability solution of prestressed bolt tension design value in various excavation stages can be obtained. The arrangement of its prestressed anchor force reflects that the layout of the lower part of bolt and the calculation of slope reinforcement is in line with the actual. These indicate that the method is reasonable and practical.

scholarly journals Improving mesoscale wind speed forecasts using lidar-based observation nudging for airborne wind energy systems

2019 ◽  
Vol 4 (4) ◽  
pp. 563-580
Author(s):  
Markus Sommerfeld ◽  
Martin Dörenkämper ◽  
Gerald Steinfeld ◽  
Curran Crawford
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Energy Systems ◽  
Stability Conditions ◽  
Data Set ◽  
Advantages And Disadvantages ◽  
Wide Range ◽  
Lidar Measurements ◽  
Wind Energy Systems ◽  
The Impact

Abstract. Airborne wind energy systems (AWESs) aim to operate at altitudes above conventional wind turbines where reliable high-resolution wind data are scarce. Wind light detection and ranging (lidar) measurements and mesoscale models both have their advantages and disadvantages when assessing the wind resource at such heights. This study investigates whether assimilating measurements into the mesoscale Weather Research and Forecasting (WRF) model using observation nudging generates a more accurate, complete data set. The impact of continuous observation nudging at multiple altitudes on simulated wind conditions is compared to an unnudged reference run and to the lidar measurements themselves. We compare the impact on wind speed and direction for individual days, average diurnal variability and long-term statistics. Finally, wind speed data are used to estimate the optimal traction power and operating altitudes of AWES. Observation nudging improves the WRF accuracy at the measurement location. Close to the surface the impact of nudging is limited as effects of the air–surface interaction dominate but becomes more prominent at mid-altitudes and decreases towards high altitudes. The wind speed frequency distribution shows a multi-modality caused by changing atmospheric stability conditions. Therefore, wind speed profiles are categorized into various stability conditions. Based on a simplified AWES model, the most probable optimal altitude is between 200 and 600 m. This wide range of heights emphasizes the benefit of such systems to dynamically adjust their operating altitude.

scholarly journals Stability conditions of the Vistula Valley attained by a multivariate approach – a case study from the Warsaw Southern Ring Road

Geologos ◽  
2015 ◽  
Vol 21 (4) ◽  
pp. 249-260 ◽  
Author(s):  
Łukasz Kaczmarek ◽  
Paweł Dobak
Keyword(s):  
Slope Stability ◽  
Road Traffic ◽  
Dynamic Loads ◽  
Ring Road ◽  
Load Factors ◽  
Geological Conditions ◽  
The Impact ◽  
Slope Design ◽  
Calculation Models

Abstract Localised landslide activity has been observed in the area of the plateau slope analysed, in the vicinity of the planned Warsaw Southern Ring Road. Using calculation models quantitative and qualitative evaluations of the impact of natural and anthropogenic load factors on slope stability (and hence, safety) are made. The present paper defines six stages of slope stability analysis, leading to an indication of optimum slope design in relation to the development planned. The proposed procedure produces a ranking of factors that affect slope stability. In the engineering geological conditions under consideration, the greatest factors impacting degradation and failure of slope stability are changes in soil strength due to local, periodic yielding and the presence of dynamic loads generated by intensification of road traffic. Calculation models were used to assess the impact of destabilisation factors and to obtain mutual equivalence with 3D-visualisation relations. Based on this methodology, various scenarios dedicated to specific engineering geological conditions can be developed and rapid stability evaluations of changing slope loads can be performed.

Study of Luming Molybdenum Mine West Zone EH4 Geophysical Prospecting and the Geological Structure Influence on Slope Stability

2014 ◽  
Vol 881-883 ◽  
pp. 1719-1725
Author(s):  
Zhi An Huang ◽  
Huan Yong E ◽  
Ying Hua Zhang ◽  
Yu Kun Gao ◽  
Ming Shan Gong
Keyword(s):  
Slope Stability ◽  
Geological Structure ◽  
Slope Instability ◽  
Inversion Method ◽  
Geological Condition ◽  
Geological Structures ◽  
Alluvial Deposits ◽  
Detection Point ◽  
Mine Slope ◽  
The Impact

As the geological condition of western Luming molybdenum mine is broken and there are faults through, to find out the geological structures of west mine is quite significant for the study of Luming mine slope stability. With EH4 geophysical technology to detect west Luming molybdenum geological condition, the data of the detection point was collated and sorted out, through the inversion method, two faults F3 and F4 was inferred in the west zone of LuMing mine, which is likely to cause slope instability phenomena. What is more, at the northwest of the pit, lithology with water was composed of alluvial deposits and broken sediments, the depth of the strata with water is more than 80 miles. So the impact of water on slope stability should be fully considered during mining process.

Application of Electrical Resistivity Tomography (ERT) survey for investigation of the landslide: a case study from Taprang landslide, Kaski district, west-central Nepal

2020 ◽  
Vol 60 ◽  
pp. 103-115
Author(s):  
Ashok Sigdel ◽  
Radha Krishna Adhikari
Keyword(s):  
Electrical Resistivity ◽  
Slope Stability ◽  
Electrical Resistivity Tomography ◽  
Slip Surface ◽  
High Resistivity ◽  
Resistivity Tomography ◽  
Central Nepal ◽  
West Central ◽  
Gravelly Soil ◽  
Wide Range

The depth of the slip surface and thickness of the overburden deposit play a major role in assessing the slope stability of a landslide. Electrical Resistivity Tomography (ERT) survey was carried out in the Taprang Landslide, Kaski district, west- central Nepal to determine subsurface lithological conditions, depth and geometry of the slip surface. Wenner and dipole- dipole arrays were mainly applied in this ERT survey. The electrical resistivity survey revealed that there is a wide range of resistivity value which shows different kinds of layers in the subsurface, and the boundaries between these layers played a significant role to identify the slip surface. The data show mainly three layers from surface to bottom. An upper layer represents the dry to saturated colluvium and sandy gravelly soil (500 to 8000 Ωm), the middle layer is highly –saturated soil with low resistivity value (100–700 Ωm) and unweathered fresh bedrock of schist and quartzite with high resistivity value (1000 to 8000 Ωm) at the bottom layer. The slip surface is considered as depth 25 m at the crown, 10–20 m at the main body part, and below 50 m at the toe and curved in geometry which indicates the rotational type of landslide. Investigation of the slip surface in a landslide using the ERT survey aids to know the slope stability.

Engineer Solutions Decreasing Seepage Losses From Enguri Pressure Tunnel

2014 ◽  
Author(s):  
M. Kalabegishvili
Keyword(s):  
Geological Structure ◽  
Concrete Lining ◽  
Design Decision ◽  
Diversion Tunnel ◽  
Pressure Tunnel ◽  
Geological Conditions ◽  
Design Values ◽  
Seepage Losses ◽  
Shotcrete Lining ◽  
The Impact

The majority of pressure tunnels are designed with pervious concrete lining, considering limited parameters (quantity and opening) equidistributed cracks. In general, according to the requirements of building specifications admissible seepage losses from tunnel shall not exceed 1% of HPP design discharge. As shown by the operation of HPP’s the value of seepage losses is in reality much higher than the acceptable one. The Inguri HPP pressure tunnel (15 km in length and 9.5 m in diameter) passes in complex geological conditions. The maximum value of pressure at the beginning and end of tunnel is, correspondingly, 110–175 m, while the water level variability in the reservoir is 90 m. The main characteristic of the structure of diversion tunnel is that in the main part of its length it is represented as a single complex: concrete lining (0.5 m thick) with strengthened grouting zone (6 m deep). Such design decision replaced more traditional structures, e.g. strengthened concrete, combined or metal linings. The internal pressure of tunnel is borne by the monolithic mass formed by reinforcement grouting. Thereby lining operation is completely dependent on the parameters characteristic for the zone of strengthened grouting (resilient backpressure and perviousness), which must satisfy design values. Thus reinforcement grouting, along with filling grouting are integral parts of pressure tunnel, without which the operation of structure is practically impossible. At the initial stage of operation (in 1985, at the low level in the reservoir and under the impact of the increase of pressures from massif the loss of lining stability (of the wall and inverted arch) occurred. Presently, based on general assessment the seepage losses developed from tunnel reach up to 10 m3/sec, which thrice exceed the design ones. As a result of rehabilitation works (massif grouting and shotcrete lining) conducted in 2006 in certain sections of tunnel seepage losses were temporarily reduced. Subsequently seepage losses increased again due to the development of erosive leakage processes in massif. In the present work calculations were conducted of the seepage parameters and stress condition of the “tunnel-massif” system during filling and discharge of reservoir using a static-seepage coupled scheme, in which a complex geological structure of massif (anisotropy, presence of cracks), the deformation of massif and seepage body force developed in it are taken into consideration. The processes developed during operational period, including depression surface enlarged and the loss of concrete lining stability, are also analyzed. Inguri HPP is Georgia’s powerful energy object (capacity – 1300 MW, design head – 450 m). Clearly the reduction of seepage losses has a great impact on power generation. In future the rehabilitation of tunnel is envisaged, as alternative options of which shotcrete lining is viewed, the same with strengthening grouting zone and stressed lining (with expanding cement). The present work presents part of the research.

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