Kinematic analyses of different types of rock slope failures. The factor of safety for rock slope stability shall be 1. The slope stability of the itakpe iron ore mine has been carried out using computer software, rockpack iii. Under kinematic sensitivity, users now have an option to output the slope dip direction plot as a polar radial chart type. Conclusions and recommendations primary rock cut area plane failure. Dips now gives users the option to perform a set vs. Introduction in soils, slope failures range from being circular in relatively. Canadian geotechnical society, 1992, canadian foundation engineering manual. In rock slopes plane, wedge, toppling and rock fall are common modes of failures tang et al. The use of lidar for evaluating geologic structure related to. One hundred and twenty three dip and dip direction values were obtained using compass clinometer. Rock slope stability analysis utilization of advanced. For toppling failures to take place, the discontinuity causing failure must be inclined parallel or almost parallel to the cutface 14.
Kinematic analysis rock slope wedge failure similar to planar failures, seve ral conditions relating to the line of intersection must be met for wedge failure to be kinematically admissible. Its failure that gives you the proper perspective on. How can i obtain the safety factor against toppling failure. You should see the stereonet plot view shown in the following figure. If this type of structure is present, the bench face height should be limited to a distance approximately equal to the bench width. Analysis of wedge failure considering only frictional resistance resolution of forces to calculate factor of safety of wedge. Toppling occurs as movement due to forces that cause an overturning moment about a pivot point below the centre of gravity of the unit. The application of goodman and brays limit equilibrium analysis of multiblock toppling failures to these three slopes is demonstrated. Figure 2 shows an example of the bedding plane and joints from cut 1 represented as poles and planes on a stereonet. One interest aspect of this sequence is the initiation of the topppling failure. Kinematic analysis is used to identify potential failure modes of rock slope.
Highlights dipanalyst is an application software that is designed to perform kinematic analysis of rock slopes. Failure of a slope in the form of wedge can occur when wo rock masses slide along t. Foundation engineering rock slopes, fhwa hi99007, 1998. Nhdot guidelines for geotechnical engineering and geological. Stereonet segments that are coloured on the number of points in each segment. A different quantitative approach that does not require tightly clustered discontinuity sets can be performed by dipanalyst 2. Pdf stability analysis of a railway trench by using. In such cases, the rock mass behaves like inclined. Flexural toppling is a mode of failure that may occur in a wide range of layered rock strata in both rock slopes and large underground excavations. Contents scoo o t n nvironent 4 introduction to stereonets a stereonet is a lower hemisphere graph on to which a variety of geological data can be plotted. Planar, wedge and toppling failures shall be analyzed for potential occurrence for each rock slope, and each. Kinematic analysis dialog simply input the slope orientation and friction angle, choose the failure mode, and a template is overlaid on the stereonet, highlighting the critical zone. Toppling rock slope failures examples of analysis and.
Flexural toppling is one of the wellknown modes of the failure. Similarly, toppling failure is not expected to occur because of the orientation of the discontinuities and the slopes in the studied area. This classic handbook deals with the geotechnical problems of rock slope design. Face 2 of the limestone quarry is not susceptible to wedge failure, but some part of it 40%, faces the risk of plane failure while up to 50% of it faces the risk of toppling failure. The accompanying text to the youtube video is as follows. Slope stability analysis of itakpe iron ore mine, itakpe. Transitional failure including planar sliding, wedge. Stability analysis and the stabilisation of flexural. A joint set was found in daylight envelope of toppling failure, while another.
Introduction to stereonets 4 stereonet terminology 6 setting up a stereonet 7. The itakpe iron ore mine was divided into four benches. It can be noted that pole of joint set 1m fall at the boundary of outlined toppling region enclosed by the slip limit and kinematic bounds, therefore this specifies a toppling failure risk of about 50 %. Assessing and monitoring open pit mine highwalls jami m. A stereonet of the discontinuities set at each quarry was drawn to determine the potential modes of failure. Kinematic analyses of different types of rock slope. For the love of physics walter lewin may 16, 2011 duration. Tutorial 07 kinematic analysis flexural toppling in dips.
Plane failure potential exists with discontinuities a and b along the primary rock slope. Toppling failure is one of the most common modes of failure of rock slopes in layered rock strata. A dry slope condition shall be analyzed, and a partially saturated slope shall be analyzed. In toppling failure the direction of dip of plane is usually towards the rock massive. Plane failure will be controlled to a large extent by. Figure 4a illustrates cut face 2 for toppling failure type. Technical committee responsible for the formulation of this standard is given in annex a. A toppling failure may result when a steeply dipping discontinuity is parallel to the slope face within 300 and dips into it hoek and bray, 1981. Kinematic analysis wedge failure 2 of 57 erik eberhardt ubc geological engineering eosc 433 2017. The use of lidar for evaluating geologic structure related. Assessing the stability of road cuttings on the zuurberg. Whether youre involved in surface mine design, surface mine production, construction, education, or regulation, this is an important book for your library. Toppling failure occur as a result of sliding and or toppling of individual slopes of rock 14. Dipanalyst can perform a newly introduced quantitative approach for kinematic analysis.
Pdf an important step in designing engineering structures in rocky areas is evaluation the stability of rock slopes. The main objectives of slope stability analysis are finding endangered areas, investigation of potential failure mechanisms, determination of the slope sensitivity to different triggering mechanisms, designing of optimal slopes with regard to safety, reliability and economics, designing possible remedial measures, e. This will help catch any toppling material and decrease the chances of impacting equipment working on the pit floor. It can be concluded that analyses of discontinuity orientation in relation to cut face direction in. Ellen degeneres view this email in your browser basic kinematic stability analysis is available for planar, wedge and toppling failures. Set analysis when considering wedge sliding or direct toppling failure modes in kinematic analysis. The requirement for the occurrence of a toppling failure according to goodman 1989 is if. Mesh repair tool that automatically fill holes in meshes apparently superior to many of the mine design software tools. The use of lidar for evaluating geologic structure related to rock slope safety and stability geohazards impacting transportation in appalachia th annual technical forum. Bedding plane and joints from cut 1 represented as poles and planes. For plane failure to occur in slope there must be lateral release surfaces which will allow a block of finite. Analysis of flexural toppling at australian bulk minerals savage river mine bruce hutchison1, kevin dugan2 and michael coulthard3 abstract the savage river iron ore mine, located in northwest tasmania, was opened in 1968 to produce iron ore.
In d l d k l f l ll d d a moderately jointed rock mass, slope failure is generally dictated directly by the presence of discontinuities, which act as planes of weakness within the rock. Landslide can result either from rock failure or soil failure. According to goodman 1989, a toppling failure involves interlayer slip movement figure 2. The very first image of the sequence is the one below. Kinematic slope stability analysis via stereonet projection. Its failure that gives you the proper perspective on success.
It has been written for the nonspecialist mining or civil engineer, with worked examples, design charts, coverage of more detailed analytical methods, and of the collection and interpretation of geological and groundwater information and tests for the mechanical properties of rock. Wedge failures involve a failure mass defined by two discontinuities with a line of intersection that is inclined out of the slope face figure 151b, toppling failures involve slabs or columns of rock defined by discontinuities that dip steeply into the slope face figure 151c, and circular failures occur in rock masses that are. Dipanalyst also can perform the traditional stereonet based kinematic analysis. We will discuss this topic with the help of a few questions. I am not sure what this cloud of dust represents any thoughts. Calculation of the daylight envelope for plane failure of. Slip or failure zone is a thin zone of soil that reaches the critical state or residual state, resulting in movement of the upper soil mass.
Calculation of the daylight envelope for plane failure of rock slopes r. There are three modes of failures that can be identified from a stereogram, i. Automated kinematic analysis of rock slope stability sciencedirect. It describes the basic rock slope failure modes and methods of analysisboth kinematic and kinetic techniques. There are number of conditions that must exist in a rock slope for planar failure to. A new video has appeared on youtube showing a time lapse sequence of photographs of a toppling failure that occurred at 12. Analysis of flexural toppling at australian bulk minerals. At the giants causeway failures usually occur along structural discontinuities present in columns of middle basalts, but they can also happen on tension failure structures.
Mar 24, 2016 for the love of physics walter lewin may 16, 2011 duration. Toppling can occur when vertical or nearvertical structures dip toward the pit. A slope failure adjacent to a roadway is shown in figure 16. Planar failure of rock slope occurs when the mass of rock in a slope slides down along a weak plane. Kinematic analyses of different types of rock slope failures in a. Failure modes in rock and soil slopes slope failure. Toppling is a mode of failure that involves the overturning of interlocked columns. The potential for toppling can be identified using the graphical construction on a stereonet. Slope stability analysis of itakpe iron ore mine, itakpe, nigeria. Face 2 of the limestone quarry is not susceptible to. Toppling toppling failure definition jee class 1112. The wall was not designed to resist the passive loads to which it was subjected. Whenever rock mass is composed of a set of parallel discontinuities dipping steeply against the excavated face plane, the rock mass will have the potential of flexural toppling failure as well. The distinct element analysis of toppling failure mechanisms.
For toppling failure, this parameter adopts the value 1. The use of lidar for evaluating geologic structure related to rock slope safety and stability geohazards impacting transportation in appalachia th annual technical forum harrisonburg, va. Toppling is a phenomenon that generally happens when force is applied to a body of the smaller base area. Slope failures are essentially natural hazards that occur in many areas over the world. Bending failure of a 36inch wide flange hbeam retaining wall constructed at the base of a creeping slope in richmond, california, along a state route. Toppling rock slope failures examples of analysis and stabilization. The results of the kinematic analyses indicate that no failure e. May 30, 2008 stereonet plots of the primary and side cuts with discontinuity group orientations are provided on plates 2 and 3, respectively. Kinematic analysis was used to investigate different rock slope failure modes on stereonet pole plotting easily. Popularly known as landslides, slope failures describe a wide variety of mechanisms that cause the outward or downward movement of slopeforming materials like rock, soil or landfills. Detailed study of rock slopes is needed if smr is found to be less than 60 or slope appears to be in distress.
It can be noted that pole of joint set 1m fall at the boundary of outlined toppling region enclosed by the slip limit and kinematic bounds, therefore this specifies a. Stability analysis and the stabilisation of flexural toppling. Erik eberhardt university of british columbia geological engineeringearth and ocean sciences, ubc, 6339 stores rd. Stereographic plot showing requirements for a plane failure hoek and bray, 1981, watts 2003. The failed soil mass can move very quickly over large distances. Ki ti a l i i kinematic analysis i slopes 1 of 36 erik eberhardt ubc geological engineering isrm edition. Rock failure modes rock slope may fail in one or more different modes plane failure wedge failure circular failure block toppling flexural toppling rock falls this is one of the simplest modes of failure. All data from rock slope kinematic stability analysis, rock material testing and. Wedge failure on two planar failure in rock in which a intersecting discontinuities with discontinuity daylights the a line of intersection which slope face daylights the slope figure 151 facing pages types of rock slope failures. For shear failure to occur, the discontinuity surfaces must either dilate, allowing asperities to override one another, or shear through the asperities. Three case histories of toppling failures of rock slopes, and the methods used to ensure that failure did not disrupt operations below the slope, are described. At the time the slope had been excavated at 4445o over a vertical height of 107 m, above a 35m wide berm.
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