ENSURING THE STABILITY OF INTERNAL DUMPS ACCORDING TO THE RESULTS OF PHYSICAL AND MECHANICAL PARAMETERS OF SOILS

Purpose. The paper considers the issues of ensuring the stability of internal dumps consisting of soft rocks. This issue is relevant because the stability of quarry boards and dumps affects the safety of work in quarries. Methodology. When assessing the stability of slopes, the method of determining the minimum coefficient of stability, equal to the ratio of restraining forces to shear forces that arise in the slope array. Findings. The calculation and assessment of the stability of the slopes of the dumps are carried out on the example of Malyshevsky rutile-zircon-ilmenite deposit. The geological structure of the deposit overburden is represented by loess-like loams, red-brown clays, gray-green clays, fine-grained sands. To ensure the stability of internal dumps, the selective formation of dumps is proposed, which is presented in this paper in two ways. In the first variant, the dumping of Sarmatian gray-green clays into the lower part of the heap, which are weakly permeable and have low strength, is considered. In the second variant, a layer of Sarmatian sands is poured into the base of the dump. According to the normative value of the coefficient of stability margin, depending on the physical and mechanical properties of the rocks that make up the array, the optimal height and slope angle of the dump are determined. When assessing the stability of the slopes of the dump, the impact of groundwater and the possibility of location in the developed space of the tailings were also taken into account. Originality and Practical implications. Studies have shown that the most rational option is the formation of internal heaps with embedding in the base of the lower tier of the heap with a height of 40 m layer of Sarmatian sands; in the case of embedding in the lower part of the inner heaps of gray-green clays, it is advisable to form the lower tier of the heap with 2 sub-tiers up to 20 m high; the upper tier of the dump is recommended to be formed by one massif 26 m high. Besides, in the produced space of the quarry, the location of the tailings is possible in case of dumping Sarmatian sands into the base of the dump.

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Optimal profile for concave slopes under static and seismic conditions

Canadian Geotechnical Journal ◽

10.1139/cgj-2016-0057 ◽

2016 ◽

Vol 53 (9) ◽

pp. 1522-1532 ◽

Cited By ~ 3

Author(s):

Farshid Vahedifard ◽

Shahriar Shahrokhabadi ◽

Dov Leshchinsky

Keyword(s):

Limit Equilibrium ◽

Stable Configuration ◽

Preliminary Evaluation ◽

Construction Technology ◽

Stability Of Slopes ◽

Optimal Profile ◽

Stabilized Soil ◽

The Stability ◽

Comparison Of The Results ◽

The Impact

This study presents a methodology to determine the stability and optimal profile for slopes with concave cross section under static and seismic conditions. Concave profiles are observed in some natural slopes suggesting that such geometry is a more stable configuration. In this study, the profile of a concave slope was idealized by a circular arc defined by a single variable, the mid-chord offset (MCO). The proposed concave profile formulation was incorporated into a limit equilibrium–based log spiral slope stability method. Stability charts are presented to show the stability number, MCO, and mode of failure for homogeneous slopes corresponding to the most stable configuration under static and pseudostatic conditions. It is shown that concave profiles can significantly improve the stability of slopes. Under seismic conditions, the impact of concavity is most pronounced. Good agreement was demonstrated upon comparison of the results from the proposed method against those attended from a rigorous upper bound limit analysis. The proposed methodology, along with recent advances in construction technology, can be employed to use concave profiles in trenches, open mine excavations, earth retaining systems, and naturally cemented and stabilized soil slopes. The results presented provide a useful tool for preliminary evaluation for adopting such concave profiles in practice.

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Study of the Stability of a Soil-Rock Road Cutting Slope in a Permafrost Region of Hulunbuir

Advances in Civil Engineering ◽

10.1155/2020/6701958 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Yuxia Zhao ◽

Jun Feng ◽

Kangqi Liu ◽

Hongwei Xu ◽

Liqun Wang ◽

...

Keyword(s):

High Latitude ◽

Limit Equilibrium ◽

Slope Angle ◽

In Situ Monitoring ◽

Permafrost Region ◽

Freeze Thaw ◽

Stability Of Slopes ◽

Low Altitude ◽

The Stability ◽

Permafrost Regions

Due to the threat of global warming and the accelerated melting of glaciers and permafrost, the stability of slopes in permafrost regions has received an increasing amount of attention from scholars. However, research on the stability of soil-rock road cutting slopes in high-latitude and low-altitude permafrost regions of the Greater Khingan Mountains in the Inner Mongolia Autonomous Region has not been reported. For this reason, a study of the stability of a slope with a high ice content in section K105 + 600 to K105 + 700 of National Highway 332 is conducted. The slope is 20 m high and the slope angle is 45°, and the risk of landslides on this slope under the action of freeze-thaw erosion is very high. Because of this, field in situ monitoring, indoor freeze-thaw tests, thermal parameter tests, and ABAQUS numerical simulation models are used to study the stability of the slope. After collecting the continuous temperature, moisture, settlement, and slope deformation data, it was found that the slope was undergoing dynamic changes. The creep of shallow slopes increased with the number of freeze-thaw cycles. After approximately 150 freeze-thaw cycles, the slope safety factor was less than 1, which means that the slope had reached the limit equilibrium state. Therefore, freeze-thaw erosion greatly reduced the stability of the slope. Hence, the stability of the slope must be protected during its entire life cycle. This study provides a reference for the design and construction of road cutting slopes in the high-latitude and low-altitude permafrost regions of the Greater Khingan Mountains.

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Physical and mechanical properties of the rocks of the Starobinsky deposit forming the Third potash layer and its roof

Doklady of the National Academy of Sciences of Belarus ◽

10.29235/1561-8323-2021-65-4-484-494 ◽

2021 ◽

Vol 65 (4) ◽

pp. 484-494

Author(s):

A. B. Petrovsky ◽

V. Ya. Prushak ◽

E. A. Lutovich

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Geological Structure ◽

Mining Operations ◽

The Third ◽

Composition And Structure ◽

Mining Conditions ◽

The Stability ◽

Roof Falling ◽

Main Factor

The geological structure and the physical-mechanical properties of rocks composing and overlapping the Third potash formation in the areas of the mine field mine No. 4 JSC Belaruskali, which are scheduled to practice, are studied. The geological sections of the Third potash layer and its roof were built, the thickness of sylvinite and halite layers was measured, the roof falling of the rocks of the layer with a height of up to 20 m was assessed, and the type of immediate roof was determined by the composition and structure of its constituent rocks. It was established that the strength under uniaxial compression of both sylvinite and halite layers for the areas under consideration differs slightly. Therefore, to solve engineering problems of ensuring the stability of mine workings and to calculate fastening parameters, strength values averaged over the groups of layers can be used that correlate well with the percentage of weak and clay interlayers. The same applies to Poisson’s ratio, the values of which for various layers of formation are slightly different and can be taken by their averaging. It is shown that the main factor that negatively affects the strength of rocks occurring in the roof of the Third potash seam is the presence of weak and clay interlayers, which increases with depth. The introduction of the obtained results allows us to improve the calculation accuracy of securing mining parameters, to reduce the costs of their maintenance, and to improve the safety of mining operations in developing the Third potash formation in complex geological and mining conditions.

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Investigation on the Stability of Fissured Slopes Reinforced with Anchor Cables under Seismic Action

Mathematical Problems in Engineering ◽

10.1155/2021/9262138 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Jingwu Zhang ◽

Mingdong Li ◽

Jinxiang Yi ◽

Zhidan Liu

Keyword(s):

Axial Force ◽

Upper Bound ◽

Crack Depth ◽

Slope Angle ◽

Optimization Procedure ◽

Seismic Action ◽

Upper Bound Theorem ◽

Critical Location ◽

The Stability ◽

The Impact

Based on the upper bound theorem of limit analysis (UBLA) combined with the pseudostatic methods, this paper elaborates on a calculated procedure for evaluating fissured slope stability under seismic conditions reinforced with prestressed anchor cables. An existing simple slope case is presented as a case study in this work. The comparison is given to verify that the solution derived from this study is correct and feasible. By means of a numerical optimization procedure, the critical location of the crack is determined from the best upper bound solutions. The results demonstrate a significant influence of the depth of crack and seismic acceleration coefficient on the critical location distribution of the cracks. Meanwhile, the axial force of anchor cables is investigated via parametric studies. It is shown that the variation of the crack depth has little effect on the axial force of anchor cables. Moreover, this paper also illustrates the variation in the axial force of anchor cables under the impact of five marked factors (crack depth, anchor arrangement, anchor inclination angle, slope angle, and seismic conditions). Finally, the required critical length of the free section of anchor cables is determined to ensure the stability of fissured slopes subjected to seismic action.

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STUDY OF THE BEHAVIOR OF TANK TRUCK WITH LIQUID CARGO IN CURVED MOVEMENT

10.34220/mamsp_138-143 ◽

2021 ◽

Author(s):

E. Saprykin ◽

V. Antsiferova

Keyword(s):

Road Traffic ◽

Stability Margin ◽

Fire Fighting ◽

Heavy Duty ◽

Tank Truck ◽

Heavy Duty Vehicle ◽

Overturning Moment ◽

The Stability ◽

Two Stages ◽

The Impact

The principles of calculating the stability margin and overturning moment to ensure the safe-ty of road traffic of a heavy-duty vehicle on curved road sections are considered. Two stages of the behavior of a fire-fighting tanker are considered: during slow sliding in a skid and the impact of the car's wheels on an obstacle, followed by overturning.

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An Experimental Investigation Into the Impacts of Varying the Circumferential Extent of Tip-Low Total Pressure Distortion on Fan Stability

10.1115/gt2021-59851 ◽

2021 ◽

Author(s):

Oliver Allen ◽

Alejandro Castillo Pardo ◽

Cesare A. Hall

Keyword(s):

Total Pressure ◽

Stability Margin ◽

Jet Engines ◽

Stall Inception ◽

Stall Margin ◽

High Incidence ◽

Circumferential Extent ◽

Low Distortion ◽

The Stability ◽

The Impact

Abstract Future jet engines with shorter and thinner intakes present a greater risk of intake separation. This leads to a complex tip-low total pressure distortion pattern of varying circumferential extent. In this paper, an experimental study has been completed to determine the impact of such distortion patterns on the operating range and stalling behaviour of a low-speed fan rig. Unsteady casing static pressure measurements have been made during stall events in 11 circumferential extents of tip-low distortion. The performance has been measured and detailed area traverses have been performed at rotor inlet and outlet in 3 of these cases — clean, axisymmetric tip-low and half-annulus tip-low distortion. Axisymmetric tip-low distortion is found to reduce stall margin by 8%. It does not change the stalling mechanism compared to clean inflow. In both cases, high incidence at the tip combined with growth of the casing boundary layer drive instability. In contrast, half-annulus tip-low distortion is found to reduce stall margin by only 4% through a different mechanism. The distortion causes disturbances in the measured casing pressure signals to grow circumferentially in regions of high incidence. Stall occurs when these disturbances do not decay fully in the undistorted region. As the extent of the distorted sector is increased, the stability margin is found to reduce continuously. However, the maximum disturbance size before stall inception is found to occur at intermediate values of distorted sector extent. This corresponds to distortion patterns that provide sufficient circumferential length of undistorted region for disturbances to decay fully before they return to the distorted sector. It is found that as the extent of the tip-low distortion sector is increased, the circumferential size of the stall cell that develops is reduced. However, its speed is found to remain approximately constant at 50% of the rotor blade speed.

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Rockfall hazard in Greece.

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.10982 ◽

2016 ◽

Vol 47 (3) ◽

pp. 1429 ◽

Cited By ~ 2

Author(s):

H. Saroglou

Keyword(s):

Slope Angle ◽

Block Size ◽

Geological Structure ◽

Archaeological Sites ◽

Rainfall Events ◽

Rockfall Hazard ◽

Rock Formations ◽

Specific Factors ◽

The Impact ◽

Of Greece

The geological structure of Greece (frequent occurrence of rock formations, existence of faults and fracturing of rocks), the steep topography and mountainous terrain as well as its high seismicity, creates a significant rockfall hazard. During the last decades, rockfalls in Greece are becoming a frequent phenomenon due to the increase of intense rainfall events but also due to the extension of human activities in mountainous areas. The paper presents rockfall hazard in Greece trough an inventory of rockfalls and investigates the correlation of specific factors, namely: a) triggering mechanism (rainfall, seismicity), b) slope angle, c) lithology, d) fault presence, e) block size in the probability of occurrence of these, based on a statistical approach. The time and space frequency of the events is also investigated. Finally, the impact of the events on human and infrastructures (transportation infrastructure, inhabited areas, archaeological sites) is discussed.

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Kajian Geoteknik Untuk Desain Pit Tambang Batugamping Di Daerah Karang Dawa, Kecamatan Margasari, Kabupaten Tegal, Jawa Tengah

PROMINE ◽

10.33019/promine.v6i2.778 ◽

2018 ◽

Vol 6 (2) ◽

pp. 5-15

Author(s):

Mersi Abadi ◽

Arifudin Idrus ◽

I Gede Budi Irawan Budi Irawan

Keyword(s):

Limit Equilibrium ◽

Physical And Mechanical Properties ◽

Secondary Data ◽

Sample Surface ◽

Field Work ◽

Raw Material ◽

Petrographic Analysis ◽

Central Java ◽

Stability Of Slopes ◽

The Stability

Location of research situated in the village Karangdawa, district Margasari, Tegal Regency, Central Java. The location of the research is the exploration Licences PT. Indocement Tunggal Prakarsa Tbk., with commodities limestone. This research is aimed at mengetahuikualitas, batugampingserta reserves and resources geotechnical model based on the geological model. Geotechnical models also determined based on the model of rockmass used slope stability analysis as a model to design the mine pit. The methods used in this research include field work in the form of observation of outcrops of rocks and develop the sample, as well as laboratory analysis in the form of analysis of petrographic analysis and XRF using the sample surface, analysis of physical and mechanical properties of the rock mass classification, as well as rocks based on Geological Strenght Index (GSI) uses a secondary data in the form of core data drilling. Analysis of the stability of slopes in this study using the method of limit equilibrium (limit equilibrium method). Interpretation and correlation of data indicating that the drilling core location stratigraphic research is composed by three units of rock: limestone, batulempung, as well as sandstones. XRF analysis results and modeling geology suggests the quality of limestone meet cement raw material standards as to the amount of 13,180,000 tons of limestone resources. The geometry of the slope resulting from the analysis of the stability of slopes of which are: single slope height of 10 meters, the angle of slope of a single 80-degree slope, the slope of the overall 48 degrees, 50 degrees, 60 degrees, 54 degrees, the wide level of 8.31 meters. Limestone reserves estimation is determined only on the basis of consideration of the mine pit design and ultimate pit limit which is limited by the territory of IUP. Backup tertambang (mineable reserve) limestone amounted to 7,477,000 tonnes.

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Research on the Impact of the Water-Level-Fluctuation Zone on Landslide Stability in the Three Gorges Reservoir Area

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.188.37 ◽

2012 ◽

Vol 188 ◽

pp. 37-44 ◽

Cited By ~ 2

Author(s):

Hong De Wang ◽

Qiang Yang ◽

Shu Hua Pan ◽

Wei Cui Ding ◽

Yong Long Gao

Keyword(s):

Mechanical Properties ◽

Water Level ◽

Pore Water Pressure ◽

Water Pressure ◽

Physical And Mechanical Properties ◽

Seepage Field ◽

Reservoir Water ◽

Landslide Stability ◽

The Stability ◽

The Impact

Taking the Lijiapo landslide in Three Gorges Area as an example, the study on the impact of seepage field changes caused by water level fluctuation on reservoir landslide stability was carried out. In order to find out the variation in slope stability when the reservoir water level changes at different rate, the stability calculation model was established adopting the Seep module and Slope module of Geoscience software GeoStudio, and calibrated with a long sequence of real-time monitoring data, based on the landslide survey data and test data. The results show that the reservoir landslide stability affected by the seepage field changes with changing reservoir level is controlled by a variety of factors, including the hydrodynamic pressure, hydrostatic pressure, uplift force, physical and mechanical properties (с, φ value change). When the water level fluctuates at a high rate, the impact of the seepage field changes on the stability is mainly affected by the pore water pressure before the stability reaches the extremum, while after the extremum, with the further infiltration or drainage of reservoir water, it is mainly affected by the change of physical and mechanical properties. When the water level fluctuates at a lower rate, the pore water pressure, uplift force and physical and mechanical properties are the dominant factors.

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METHODS FOR THE DETERMINATION OF THE STABILITY OF THE EARTH CONSTRUCTION DEVICE

Bridges and tunnels Theory Research Practice ◽

10.15802/bttrp2017/159216 ◽

2017 ◽

pp. 81-87

Author(s):

О. L. TIUTKIN ◽

О. І. DUBINCHIK ◽

V. R. KILDEEV

Keyword(s):

Geological Structure ◽

Calculation Model ◽

Theoretical Research ◽

Advantages And Disadvantages ◽

Earth Construction ◽

Stability Of Slopes ◽

Research Findings ◽

The Stability ◽

Selection Of

Purpose. Conduct a generalized analysis of methods for assessing the stability of slopes and slopes, which are currently used. An assessment of the stability of slopes and slopes can be carried out only on the basis of a comprehensive study using different methods. Methodology. Theoretical research. Findings. The analysis carried out in the framework of this study to determine the stability characteristics of landslide slopes suggests that the coefficient of stability depends directly on the nature, steepness and geological structure of the slope. Originality. The calculation scheme for determining the coefficient of stability directly depends on the methods chosen. The calculation will be reliable in the event that the corresponding scheme is more accurately and more detailed. Practical value. The use of each of the methods considered provides for the use of a number of special geotechnical surveys and the selection of a calculation model by comparing advantages and disadvantages.

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