The resulting failure surface is often approximately circular in shape. In this case, some rock blocks fail due to tensile bending stresses and some overturn under their own weights. 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. Strength in plastic materials is defined as the level of stress at failure. What is the bearing capacity of rock on surface an at depths. A transfer coefficient method for rock slope toppling.
Ab as a specific instability of rock slope, an antidip stratified rock slope is different from the sliding one, and the failure mechanism has not been clarified yet. As a discrete numerical method, discontinuous deformation analysis dda in the present study, a threedimensional 3d dda method was conducted to study the toppling failure mechanisms of rock slopes by introducing the global contact theory. The series may include edited volumes, textbooks, reference works and books on advanced scientific topics. Given the strongly nonassociative character of topplingsliding rock slope failures, examples of experimental data were chosen from the rock mechanics. Rockfall and toppling failure simulation of rock slopes using. Rock slope engineering civil and mining 4th edition by duncan. The mechanism of flexural toppling failure of jointed rock slopes has been investigated through a series of centrifuge experiments conducted on models manufactured from two types of materials brittle. This site is like a library, use search box in the widget to get ebook that you want. Mechanisms of slope failure other than pure sliding springerlink. For the love of physics walter lewin may 16, 2011 duration.
Pdf rockfall and toppling failure simulation of rock slopes. The key reasons for the toppling failure of plate rock masses are the increasing weight of the upper rock soil aggregate and the mountain erosion by river water. Nonassociative limit analysis of the topplingsliding. Finally, the topping failure of left bank of one high dam is simulated. As a discrete numerical method, discontinuous deformation analysis dda is wellsuited for simulating the movement process, contact transformation, and large displacement and deformation of rock block systems, which are formed in jointed rock masses. Rock mechanics an introduction for the practical engineer. We will discuss this topic with the help of a few questions. Flexural toppling is one of the wellknown modes of the failure. The book considers fundamental geological processes that give rise to the nature of rock masses and control their mechanical behavior.
Toppling failure toppling failures occur when columns of rock, formed by steeply dipping discontinuities in the rock rotates about an essentially fixed point at or near the base of the slope followed by slippage between the layers. Finally, a real case study is used for the practical verification of the suggested method. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. Numerical analysis of stability for an antidip stratified. The spectrum of rock dynamics is very wide and it includes the failure of rocks, rock masses and rock engineering structures such as rockbursting, spalling, popping, collapse, toppling, sliding, blasting, nondestructive testing, geophysical explorations, science and engineering of. Rock mechanics studies to analyse toppling failure authors.
This extended third edition includes an additional chapter on foundations on jointed rock. Limit analysis is a powerful procedure which is widely used in geotechnical engineering for the analysis of collapse states. Failure modes in rock and soil slopes slope failure. Modelling of progressive and instantaneous failures of foliated rock. It contains an introductory chapter explaining the role of rock failure in engineering projects plus a summary of the theories governing rock failure and an explanation of the. Kinematic analyses of sliding and toppling failure of double free face rock mass slopes. Toppling failure is one of the most common modes of failure of rock slopes in layered rock strata. It subsquently deals in detail with explaining, simulating and illustrating rock failure in laboratory and field. This toppling action is due to the columns center of gravity lying outside the base dimensions.
The ultimate tensile length of a cantilever slab flexural toppling of strati. Physical and theoretical modeling of rock slopes against. Fundamentals of rock mechanics, fourth edition, by jaeger, cook and zimmerman, blackwell publishing. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. In plastic material, specific point of failure difficult to. Practical rock mechanics provides an introduction for graduate students as well as a reference guide for practicing engineering geologists and geotechnical engineers. Numerical modeling of rockslope instability chapter. Failure of a brittle rock point when the rock loses all resistance to stress and crumbles. Rock slope stability in surface excavations, from planar block and wedge slides to rotational and toppling failures shaft and tunnel stability, ranging from. Apr 25, 2017 toppling failure toppling failures occur when columns of rock, formed by steeply dipping discontinuities in the rock rotates about an essentially fixed point at or near the base of the slope followed by slippage between the layers. In this chapter we present the current state of the art, beginning with simple kinematic and limit equilibrium approaches and then moving on to continuum and discontinuum modeling techniques. The spectrum of rock dynamics is very wide and it includes the failure of rocks, rock masses and rock engineering structures such as rockbursting, spalling, popping, collapse, toppling, sliding, blasting, nondestructive testing, geophysical explorations, science and engineering of rocks.
Rock slope engineering civil and mining 4th edition duncan c. Some field examples of toppling failure geotechnique. This paper describes three field examples which came from contrasting structural settings. A general analytical solution for the required anchor force in rock slopes with toppling failure. I strongly suggest it at least for all the professionals. Nonassociative limit analysis of the topplingsliding failure of rock.
New stability calculation method for rock slopes subject. Rock dynamics has become one of the most important topics in the field of rock mechanics and rock engineering. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rock fill dams, embankments. This book is an very good update including many more case histories of a classical text. It contains an introductory chapter explaining the role of rock failure in engineering projects plus a summary of the theories governing rock failure and an explanation of the computer simulation method. Provides examples of the practice of rock mechanics to major engineering projects. The orientation data obtained were plotted on stereonets to determine pole concentration and major joint sets using dips 5. The toppling failure is related with an alternate relationship between the joint dip angle and the gradient of the cutting slope. This note provides an introduction to the mechanics of materials and structures. In the third failure, the top 8 m of a single 12 m high toppling block was removed by blasting to prevent further rotational movement. Jan 25, 2007 although rock mechanics addresses many of the rock mechanics issues which arise in underground mining engineering, it is not a text exclusively for mining applications. Stability analysis of slopes with a potential of slidehead toppling failure. The center of gravity of the column or slab must fall outside the dimension of its base in toppling failure. In this failure, rock blocks rotate about their toes and all of them overturn together.
Surface rock engineering relies greatly on the theories and techniques. Toppling toppling failure definition jee class 1112. 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. 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. 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. Much of the work that has appeared in the literature to date deals with the development of this mode in models. Click download or read online button to get toppling book now. Reliable information about the coronavirus covid19 is available from the world health organization current situation, international travel. Toppling failure occurs due to steep discontinuities in the rock which eventually leads to slippage of the layers and the outward and downward movement of a column of rock. Illustrated and explained crc press book when dealing with rock in civil engineering, mining engineering and other engineering, the process by which the rock fails under load should be understood, so that safe structures can be built on and in the rock.
An optimization of the analytical method for determining. Numerous and frequentlyupdated resource results are available from this search. The text presents a concise treatment of the physics and mathematics of a representative selection of problems from areas such as earthquake mechanics and prediction, hydraulic fracturing, hot dry rock. In order to clarify mechanism of toppling failure in rock slopes and evaluation on seismic stability, 2d joint elements around each rock column is proposed to simulate the discontinuity of rock slope, which is different from goodman joint and composed with normal spring k n and shear spring k s without volume.
Publications rock slope engineering 5th edition, 2017. A slideheadtoppling failure is a complex failure that occurs when the upper part of a slope topples and pushes the underlying soil mass or weak rock in the toe of the slope and causes a circular sliding failure. Stability analysis of slopes with a potential of slide. Kinematic assessment of rock slope stability at obajana. Modelling of progressive and instantaneous failures of. Toppling rock slope failures examples of analysis and stabilization. The expected readers of the book are all those involved in rock mechanics and rock engineering activities, in the fields of civil, mining and petroleum engineering, and engineering geology. Geotechnical characteristics and stability analysis of rock. Read toppling mechanisms of rock slopes considering stabilization from the underlying rock mass, international journal of rock mechanics and mining sciences on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at. Kinematic analyses of sliding and toppling failure of double. Rock mechanics and the design of structures in rock, l.
This classic handbook deals with the geotechnical problems of rock slope design. Toppling is a mode of failure that involves the overturning of interlocked columns. Geotechnical characteristics and stability analysis of. Toppling rock slope failures examples of analysis and. However, when applied to toppling sliding failures in rock slopes, overestimates of stability can arise, and hence limit equilibrium and dem approaches have proved more popular. The increased attention paid to experimental rock fracture mechanics has led to major contributions to the solving of geophysical problems. Structures in and on rock masses will be of interest to rock mechanics academics as well as to professionals who are involved in the various branches of rock engineering.
No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter. Rock mechanics problemsrock mechanics problems how will rock react when put to mens use. You will be introduced to and become familiar with all relevant physical properties and fundamental laws governing the behavior of materials and structures and you will learn how to solve a variety of problems of interest to civil and environmental engineers. On the other hand, topplingsliding failure can occur in flatter slopes or in larger scale slopes, where toppling columns force the rock near the toe of the slope to fail by sliding or shearing through intact material. Mechanisms of flexural toppling failure of slopes in foliated rock masses are investigated both experimentally by testing small scaled models in a centrifuge and theoretically by using a limiting equilibrium model and a finite element model based on the cosserat theory. Toppling is a phenomenon that generally happens when force is applied to a body of the smaller base area. Rock mechanics an introduction for the practical engineer parts i, ii and iii first published in mining magazineapril, june and july 1966 evert hoek this paper is the text of three lectures delivered by the author at the imperial college of. Slope failures are essentially natural hazards that occur in many areas over the world. Stability analysis of rock slopes against blockflexure.
Since the rock slope has toppling failure potential, this load will contribute to the toppling failure. The spectrum of rock dynamics is very wide and it includes the failure of rocks, rock masses and rock engineering structures such as rockbursting, spalling, popping, collapse, toppling, sli. With wide application, a solid grasp of this topic is invaluable to anyone studying or working in civil, mining, petroleum, and geological engineering. Rock mechanics studies to analyse toppling failure. Related codes and manuals from international society of rock mechanics, astm and bureau of indian standards. Here the column of rock rotates about a fixed point at the base of the slope. The last decade has seen considerable advances in the application of numerical modeling to rock slopes. When a blocky or layered rock mass is overlaid by a soil or weak rock mass, the combination of a toppling failure in the rock at the toe and a circular or noncircular sliding in the soil or weak. Toppling is a representative failure mode of discontinuitycontrolled rock slopes. Blockflexure is the most common type of toppling failure in rock slopes.
The comparative studies show that the proposed analytical approach is appropriate for the stability analysis of rock slopes against blockflexure toppling failure. Institution of mining and metallurgy, 1977 science 402. In plastic material, specific point of failure difficult to identify because deformation continues indefinitely at a constant level of stress. Oclcs webjunction has pulled together information and resources to assist library staff as they consider how to handle coronavirus. If youre a student in rock mechanics you might also read hoeks course notes. So the entire slope has a combination of circulartoppling failure potential, as shown in fig. The research work assessed the stability of rock slopes for optimum exploitation of limestone deposits at obajana in kogi state and ewekoro in ogun state.
Stability analysis of slidetoetoppling failure request pdf. This reference book provides engineers and researchers with the essential knowledge for a clear understanding of the process of rock failure under different conditions. Shear strength of rock, rock joints and rock masses problems and some solutions. Practical rock mechanics teaches from first principles and aids readers understanding of the concepts of stress and stress transformation and the practical application of rock mechanics theory. Isrm members benefit from a 40% discount on isrm book series volume purchases.
This includes professionals working in field and laboratory testing, modelling of rock structures. Geological mapping was carried out to measure the orientations of discontinuities. The basal failure plane observed in the centrifuge models, has been found to emanate from the toe of the slope, and orient at an angle. Rock slope stability charles a kliche whether youre involved in surface mine design, surface mine production, construction, education, or regulation, this is an important book for your library. International journal of rock mechanics and mining sciences 38. An ideal source for geologists and others with little background in engineering or mechanics. Lectures on rock mechanicslectures on rock mechanics. This comprehensive introduction to rock mechanics treats the basics of rock mechanics in a clear and straightforward manner and discusses important design problems in terms of the mechanics of materials. Thus, the most important thing to keep in mind is that strong rock is strong, weak rock isnt our first goal is to capture the essential. Amini, mehdi, hassan sarfaraz, and kamran esmaeili. Developed for a complete class in rock engineering, design analysis in rock mechanics, second edition uniquely combines the design of surface and underground rock excavations and addresses. Many professionals in our field consider all the books written by prof. A study of the mechanism of flexural toppling failure of rock. An introduction presents the fundamental principles of rock mechanics in a clear, easytocomprehend manner for readers with little or no background in this field.
Rock slope engineering civil engineering i am menglim. The results of this method are compared with the outcomes of the experiments. Introduction toppling failures can occur in slopes cut in rock with regularly spaced fractures which strike parallel to the slope, and dip into the face. Fully revised and updated, the fifth edition of this classic handbook, based on the original book by evert hoek and john bray, comprehensively addresses the design and excavation of rock slopes, with particular emphasis on civil engineering applications. Then, a theoretical model is proposed for rock slopes with a potential for blockflexure toppling instability. What is the response of rocks under dynamic earthquake type loading. This text can help ensure that ground models and designs are.
Failure mechanisms of toppling rock slopes using a three. In the first stage, due to rock columns deformation, soil mass moves slightly and enters into an active mode. Combined with the increasing stress and decreasing rock mass mechanics parameters, toppling failure occurs. As one type of rock slope failures, topping failure can be accurately simulated only when several aspects are correctly calculated such as deformation and stress. 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. Main fields covered by the book series rock and rock mass characterization field and laboratory testing methods in rock mechanics and rock engineering. Also, the stress in the shallow plate rock masses is increased. In such failure, some rock blocks break due to tensile stresses and some overturn under their own weights and then all of them topple together.
Scribd is the worlds largest social reading and publishing site. Blockflexure is the most common mode of toppling failure in natural and excavated rock slopes. As the shear failure occurred near the slope toe, the effects of the cohesion of the discontinuities on the stability of anaclinal layered rock slopes against flexural toppling failure and the contribution of tangential force to crosssection axial force were neglected in previous studies, and none of the experts had developed a rigorously. Part of the international centre for mechanical sciences book series cism. Kinematic analyses of sliding and toppling failure of. Stability analysis of slopes against combined circular.
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