open pit slopes face angle requirement is more than

MINING

SLOPE STABILITY ANALYSIS FOR OPEN PITS 1

& 0183; measured joint to slide into the pit within a pre-determined daylighting window, typically 50º to 60º wide 25º to 30º on either side of the normal to the wall and plotting the cumulative frequency of failed planes against the face angle. In the wedge analysis case, it文件大小: 760KB

Slope Angle Influence in the Economic Value of an Open

Currently, the Project is considering a final pit design with 44 and 48 degrees slope angle for the waste rock zone Z-1 and mineralized zone Z-2 , respectively. This Engineering Project is looking for the maximization of the Project value by varying these angles, limited for geotechnical restrictions, seeking the best combination of them and evaluating them from a technical and economic viewpoint.

Open pit mine planning considering geomechanical fundamentals

& 0183; criteria, which determine the stability of the open pit’s walls. Among these characteristics are bench face angle, bench height, berm width, inter-ramp angle, overall angle, overall height and ramp width. The determination of the geometrical components of a slope

Pit Wall Angles and Bench Width – How Do They Relate?

Typically the bench face angle “BFA” will be dictated by the rock strength, the structural fabric, and whether controlled blasting is used minimizing damage to the walls . The BFA may vary around the pit or in different rock types, but it typically is in the range of 60° to 75°.

Probabilistic approach for open pit bench slope stability

2019/7/1& 0183; These are: 1 the joint dip angle must be less than the rock slope dip angle, 2 the slope dip angle must be greater than the friction angle of the joint, and 3 the joint dip direction must range in an interval of /-20 with respect to the slope face direction.Cited by: 6

Evaluation of Open Pit Mine Slope Stability Analysis

& 0183; joints and slope face strike. It ranges from 1.0 to 0.15. The values are empirically established by the formula: F1 = 1 - Sin A 2 Where A =Angle between the strike slope face and joints.

Slope Design and Implementation in Open Pit Mines:

2012/1/1& 0183; Slopes in open pit mines must be considered as geotechnical structures. Therefore their design and implementation must be conducted with all consideration including technical, economical, environmental and safety issues.Cited by: 15

Open-pit mining - Wikipedia

Open-pit mining, also known as open-cast or open cut mining, is a surface mining technique of extracting rock or minerals from the earth by their removal from an open-air pit, sometimes known as a borrow . This form of mining differs from extractive methods that Extraction& 0183;

Surface mining planning and design of open pit mining

2016/1/9& 0183; Geology determines limits but about 58 to 72 degrees is a common range for toe to crest in open pit metal. Over-all slopes often more conservative Frequently less than 45 degrees Cannanea Mexico is nearly 60 35.

11. THE STABILITY OF SLOPES

& 0183; of the angle of shearing resistance of the soil to the tangent of the mobilised angle of shearing resistance of the soil when the cohesive component of strength is fully mobilised. One way in which this may be expressed is as follows: τ = c σn tan φ Fφ 11.4

Open pit mine planning considering geomechanical fundamentals

& 0183; criteria, which determine the stability of the open pit’s walls. Among these characteristics are bench face angle, bench height, berm width, inter-ramp angle, overall angle, overall height and ramp width. The determination of the geometrical components of a slope

Recommendations for NorthMet open pit rock slope designs NorthMet mine project

& 0183; Bench Face Angle to 70 or better, provided that experience with initial slopes, confirmed by mapping, indi es that adverse wedges and planes with dips in the 47 ° to 51 ° range are not problematic.

11. THE STABILITY OF SLOPES

& 0183; of the angle of shearing resistance of the soil to the tangent of the mobilised angle of shearing resistance of the soil when the cohesive component of strength is fully mobilised. One way in which this may be expressed is as follows: τ = c σn tan φ Fφ 11.4

Engineering appli ion of thrust block T analysis in slope stability problems in open pit

& 0183; portions intervening between slopes known as benches. In many cases, each highwall or slope is vertical for economic and technical reasons. The overall pit slope angle is defined by a straight line that joins the crests of successive highwalls or slopes up the

Chapter 7 Slope Stability Analysis

& 0183; face, with or without seepage affects, an infinite slope analysis should be conducted. Typically, slope heights of 15 to 20 ft or more are required to have this type of failure mechanism. For infinite slopes consisting of cohesionless soils which are either above the

Surface mining planning and design of open pit mining

2016/1/9& 0183; Geology determines limits but about 58 to 72 degrees is a common range for toe to crest in open pit metal. Over-all slopes often more conservative Frequently less than 45 degrees Cannanea Mexico is nearly 60 35.

GUIDELINES ON SAFETY BUND WALLS - Department of Mines,

& 0183; edge of the open pit than specified by this guideline, it must be demonstrated that the stability of the ground mass between the pit edge and the abandonment bund can be ensured for the very long term.

Designing Catch Benches and Interramp Slopes

& 0183; lnterramp Angle Bench Face Angle Bench Height Bench Width H -ta B Recommended Catch Bench Width W = 4.6 0.2H in meters lnterramp Slope Angle I = tan-1 w HHcot 8 / FIGURE 3.1 Relatlonship between lnterramp andCatch

Geotechnical guideline for terminal and rehabilitated slopes

& 0183; Table 1: Documentation required for terminal and rehabilitated slopes Hard rock buffer greater than 20m plus final depth of excavation 1 Hard rock buffer less than 20m plus final depth of excavation Soft rock - flatter than or equal to 1V:3H2 Soft rock – 1V:3H

2004G Volume 2 - A Study of Damage Profiles Behind Blasts

& 0183; 1. narrow width of blast, typically comprising no more than 4 rows of blastholes parallel to the pit wall; 2. length of blast typically at least several times greater than the width; 3. a free face, with all loose material completely removed so that unimpeded forward 4.

Integrated structural stability analysis for preliminary open pit

& 0183; A requirement during pre-feasibility and feasibility stages is to determine if the economically optimised pit slopes are stable. Based on operational requirements and on slope stability analysis results, ore-to -waste ratios SR are computed and preliminary pit

1926 Subpart P App B - Sloping and Benching

2020/8/17& 0183; Angles have been rounded off. Footnote 2 A short-term maximum allowable slope of 1/2H:1V 63º is allowed in excavations in Type A soil that are 12 feet 3.67 m or less in depth. Short-term maximum allowable slopes for excavations greater than 12 feet 3.67 m in

THE TRANSITION FROM OPEN PIT TO UNDERGROUND MINING:

& 0183; characteristics of the open pit geology, dykes, joint sets, failure mechanisms, water pressures, modes of deformation, strength properties . These models took into account the

Inter-ramp and bench design of open-pit mines: the Portage pit

& 0183; on a bench height of 20 m and bench face angles that varied from 70 to 90 . The resulting ultimate pit has a length of 2400 m and its width varies between 150 and 400 m, Fig. 4a. The depth of the pit reaches a maximum of 120 to 150 m at its southern

The Design Of Quarry Faces And Slopes Agg-Net

The reserves sterilized/lost by splitting a 20m face at 70 into 2 x 10m faces with one 7m bench amounts to 1,890 tonnes for every 10m length of face. It should be noted that the above calculations relating to face angle, bench width and face height are based on relatively short 10m lengths of quarry slope and simple geometry; they will need to be increased many times to take into account actual quarry

SLOPING AND BENCHING SYSTEMS

& 0183; greater than 8 feet but less than 12 feet, the steepest maximum allowable slope is 45 degrees from the horizontal. This translates to a 1H: 1V incline and is shown below. The maximum height of the vertical lower portion is 3.5 feet. Maximum Allowable Slope

Preliminary selection of optimum bench face angle using

& 0183; the bench width will change for each bench face angle. In this case, the minimum bench face angle must be greater than the interramp angle to ensure a bench is created. 3.2. Joint Characteristics To define the wedge geometry, the orientation

Slope stability analysis - Wikipedia

Slope stability analysis is a static or dynamic, analytical or empirical method to evaluate the stability of earth and rock-fill dams, embankments, excavated slopes, and natural slopes in soil and rock. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement.

Australian Centre for Geomechanics Conference Papers -

It was found that in general, the average as-built batter face angle for the mine survey pickup was no more than 2 degrees lower than the interpreted Sirovision model batter face angle. This work will help to drive the reconciliation process between the geotechnical design

Use of the excavation compliance indi or at the Oyu Tolgoi

& 0183; a 3 variation from design is much more significant on a 24 m high face than on a 10 m high one. The same thing applies to CBW where use of absolute variation ‐1 m, ‐3 m, etc. doesn't take account of ch bench width.

SLOPE STABILITY ANALYSIS FOR OPEN PITS 1

& 0183; measured joint to slide into the pit within a pre-determined daylighting window, typically 50º to 60º wide 25º to 30º on either side of the normal to the wall and plotting the cumulative frequency of failed planes against the face angle. In the wedge analysis case, it

Slope Angle Influence in the Economic Value of an Open

Currently, the Project is considering a final pit design with 44 and 48 degrees slope angle for the waste rock zone Z-1 and mineralized zone Z-2 , respectively. This Engineering Project is looking for the maximization of the Project value by varying these angles, limited for geotechnical restrictions, seeking the best combination of them and evaluating them from a technical and economic viewpoint.

Open pit mine planning considering geomechanical fundamentals

& 0183; criteria, which determine the stability of the open pit’s walls. Among these characteristics are bench face angle, bench height, berm width, inter-ramp angle, overall angle, overall height and ramp width. The determination of the geometrical components of a slope

Pit Wall Angles and Bench Width – How Do They Relate?

Typically the bench face angle “BFA” will be dictated by the rock strength, the structural fabric, and whether controlled blasting is used minimizing damage to the walls . The BFA may vary around the pit or in different rock types, but it typically is in the range of 60° to 75°.

Probabilistic approach for open pit bench slope

2019/7/1& 0183; These are: 1 the joint dip angle must be less than the rock slope dip angle, 2 the slope dip angle must be greater than the friction angle of the joint, and 3 the joint dip direction must range in an interval of /-20 with respect to the slope face direction.

Evaluation of Open Pit Mine Slope Stability Analysis

& 0183; joints and slope face strike. It ranges from 1.0 to 0.15. The values are empirically established by the formula: F1 = 1 - Sin A 2 Where A =Angle between the strike slope face and joints.

Slope Design and Implementation in Open Pit Mines:

2012/1/1& 0183; Slopes in open pit mines must be considered as geotechnical structures. Therefore their design and implementation must be conducted with all consideration including technical, economical, environmental and safety issues.

Open-pit mining - Wikipedia

Open-pit mining, also known as open-cast or open cut mining, is a surface mining technique of extracting rock or minerals from the earth by their removal from an open-air pit, sometimes known as a borrow . This form of mining differs from extractive methods that require tunnelling into the earth, such as long wall mining.Extraction& 0183;

Surface mining planning and design of open pit mining

2016/1/9& 0183; Geology determines limits but about 58 to 72 degrees is a common range for toe to crest in open pit metal. Over-all slopes often more conservative Frequently less than 45 degrees Cannanea Mexico is nearly 60 35.

11. THE STABILITY OF SLOPES

& 0183; of the angle of shearing resistance of the soil to the tangent of the mobilised angle of shearing resistance of the soil when the cohesive component of strength is fully mobilised. One way in which this may be expressed is as follows: τ = c σn tan φ Fφ 11.4

SLOPE FACE STABILIZATION FOR CRITICAL SLOPE SURFACES

& 0183; slope face failure and subsequent erosion. Over-steepened freshly graded or disturbed slopes are considered critical when resistance to surface erosion is low and sheer and strength resistance tolerances are exceeded. The potential for slope face failure of the

Advances in Pit Wall Mapping and Slope Assessment using

& 0183; As mining in open pits progresses deeper, keeping slopes stable becomes more complex. Multi-bench scale instabilities can result in significant economic loss. To address this concern, systematic documentation and evaluation of the performance of benches in

1985 - Price - Reclamation of Waste Rock Dump Slopes - Open Collections - UBC Library Open

& 0183; Open pit mining is carried out in a truck and shovel operation. Due to the steepness of the terrain, terraced dump slopes is to regrade slopes to a shallower angle of repose. To meet this requirement, the Kitsault dumps have been designed so that two The

Map of the potential geotechnical susceptibility for

The pit should be divided into sectors, defined by lithology, geomechanical class, structural domains and the geometric characteristics of the slopes: height, angle and direction. These sectors are temporary and dynamic, since the development of the mining is constant until reaching the final pit geometry, so they should be periodically checked.

Slope stability - SlideShare

2016/9/1& 0183; Consequently, pit slopes are formed as the ore is being extracted. It is seldom, not to say never, possible to maintain stable vertical slopes or pit walls of substantial height even in very hard and strong rock. The pit slopes must thus be inclined at some angle to 20.

Influence of Slope Curvature on Stability — PFC 6.0

The model shown in Figure 1 represents a quarter-section of an open pit. The height of the slope is 25 m, and the slope angle is 2 vertical to 1 horizontal approximately 63° . It is expected that plane-strain conditions will prevail along the plane y = -30 see Figure 2 , while axisymmetric conditions will be predominant at the plane x = 0 see Figure 3 .

Saprolite slope design at the Rosebel Gold Mine

& 0183; weathering profile along a pit face which must be mined at a lower inter-ramp angle than surrounding rock and in turn impacts stripping ratio if an over-conservative design approach is used. Saprolite slope design at the Rosebel Gold Mine 755 Rosebel geology

Overall Slope Angle vs Interramp Slope Angle - Revisited

When measured over two benches the overall slope angle blue is much steeper than the overall slope angle measured over 5 benches magenta . The overall slope angle becomes more shallow with each bench because each bench adds a fixed offset in addition to the offset due to the face angle.

High Angle Conveyor Offers Mine Haulage Savings

& 0183; This paper describes a typical open pit mine's requirements, concentrating on haulage alternatives. Definitive costs for high angle conveyorised systems are compared with truck haulage. These costs have been developed from existing current operations.

Major Mines and Projects Moa Mine

The final pit wall slopes and other geotechnical considerations are not considered a significant issue during the mining process. The bench face angle is close to vertical, often between 80 and 90 . A 2 m bench width is typical giving a lower overall slope of Haul

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