Analysis of planar failure stability in the slope stability calculation for planar failure and the wedged failure, shear strength of rock mass is dominant, and it presents the function of discontinuity strength and the paths in intact rock mass that separate the discontinuities arbanas, 2002. 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. Rock slope stability analysis a variety of engineering activities require excavation of rock cuts. Fundamentals of slope design keynote address at slope. Slope stability verification manual deep excavation llc page 11 e. Pdf a method for the design of a bolting system for rock. Ensure that the torque application is smooth and that the force causing the torque is applied through the center of the torque wrench handle. Study of effect of bolt anchorage parameters on rock slope stability by. Different rock bolt diameters and different rock bolts inclination with respect to the shear plane were tested. Stability analysis of a rock slope in himalayas 3 fig.
A rock slope with a history of block failures is to be stabilized through anchoring. Fhwahi99007 1998 which discusses geologic terms related to rock slope stability. Determining rock bolt or anchor tension using a torque. Field reconnaissance and a detailed fracture survey of the rock slopes were conducted by dr. Chapter 10 slope stability analysis nysdot geotechnical page 104 january 21, 2014 design manual 10. Drainage of water is an effective method of increasing the stability of a slope. The hoekbrown failure criterion and gsi 2018 edition. Rock slope stability analysis lec 1 linkedin slideshare. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. Determine the tension in a rock bolt or its anchor. Stability calculation model of frame supporting structure with prestressed anchor. Design and specification of remedial works methods and techniques. Rock slope stability analysis utilization of advanced numerical techniques dr.
Rock bolting design self drilling rock anchors by sinorock. Design calculation of prestressed rock bolting structures should include. The effect of length of rock bolts on the stability of. Context sensitive rock slope design solutions fhwa us. Landslide can result either from rock failure or soil failure. Tension capacity calculation of rock boltings reinforced body. By increasing the distance of rock bolts, the strength.
Also included in the document are two detailed design examples and technical specifications for ground anchors and for anchored walls. Stability calculation method of slope reinforced by. Stability analysis of bolts reinforced rock jointed slope. I am seeking an example or reference that goes through the design for a cliff face that needs to be spot stabilized with rock bolts. Rock slope stability analysis utilization of advanced. A new nonlinear hoekbrown strength reduction method based on the characteristics of a jointed rock mass is proposed. Rock slope design guide page 21 section 200 geologic explorations, data collection and presentation 201 i. Further analysis was performed on those designs which satisfy a. Slope stability analysis by strength reduction, geotechnique, 496, 835840. Including calculations for bolt diameter, bond length, bolt length, bearing plates, number of bolts for block stabilization.
Possible rightofway issues, debris containment, difficulty with drilling, and. It describes the basic rock slope failure modes and methods of analysisboth kinematic and kinetic techniques. Rock bolts have been used for years to reinforce the. Slope failure can often be catastrophic, involving the loss of considerable property and many lives.
Rock bolts jointed or sheared rock preventtreat sliding slabs concrete straps and bolts heavily jointed or soft rock prevent. A method for the design of a bolting system for rock slopes. Modem methods for design and stabilization of rock slopes were developed in the 1970s. A wide variety of rock bolt for slope stability options are available to. Pdf on nov 18, 2016, pandit bhardwaj and others published robust geotechnical design of rock bolts for stability of rock slopes using. Rock slope stability analysis according to eurocode 7. In civil engineering, projects include transportation systems such as highways and railways, dams for power production and. In the models, the pattern of parallel deterministic joints was used in spacing of 2 meters. Figure 43 depicts a rock slope stability analysis diagram assuming a tension. This type of analysis is also utilized to determine. Rock slope stability of the vmt prince william sound. The amount of detail required for different stages of the analysis depends upon whether one is designing a slope or a foundation and this difference is highlighted in figures 1 and 2.
A new rock bolt design criterion and knowlwdgebased. According to eurocode 7, several principles for stability analysis may be applied, including empirical, limit equilibrium, numerical, and probabilistic. Decreases the number of rock bolts or dowels needed in a rock slope. Slope stability examples deep excavation design and. Level 111, the most detailed sitespecific level, is intended for design of stabilization measures. The hoekbrown criterion was introduced in 1980 to provide input for the design of underground excavations in rock. Based on the failure mode of soil slope, it takes the soil, frame structure, and anchor rod rope interaction into consideration, and, according to the literature, for soil slopes and largescale rock slope structure circular sliding method is appropriate. In europe, rock slope stability analysis and slope design have to be based on eurocode 7, which is today the basic standard for geotechnical, including rock engineering, design. By analyzing the change in slope failure mode, effects of the bolt head, spacing, inclination, and arrangement on the stability of the slope are investigated. Conclusion in this research that with aim to analysis the effect of spacing of rock bolts on the stability of rock slopes is done the following results are obtained. A slope stability problem in hong kong 7 the symbols and dimensions used in these models are as follows. In general, the buckling failure may occur in the rock slopes, if the slope dips more.
Slope failures are essentially natural hazards that occur in many areas over the world. To study the effect of length of rock bolts on the stability of rock slopes, the slopes in different dips such as 30, 45, 60, and 75 were modeled by phase2 software rocscience, 1999. Whether youre involved in surface mine design, surface mine production, construction, education, or regulation, this is an important book for your library. Asuccessful rock slope stabilization program requires the integration of a number of interrelated activities, including geotechnical engineering as well as environmental and safety issues, construction methods and costs, and contracting procedures. At anchorage section, tension capacity calculation between grouting and reinforced body. The primary purpose of this project was to evaluate the stability of rock slopes of the vmt during potential earthquake conditions. Slope stability analysis geotechnical design manual m 4603 chapter 74 december 2006 slope stability analysis detailed assessment of the groundwater regime within and beneath the slope is also critical. Chapter 15 rock slope design nysdot geotechnical page 155 january 14, 2015 design manual the detailed requirements for the design of rock cuts are provided in fhwahi99007, rock slopes reference manual, publication dated 1998.
Failure modes in rock and soil slopes slope failure. This engineer manual em provides guidance for analyzing the static stability of slopes of earth and rock fill dams, slopes of other types of embankments, excavated slopes, and natural slopes in soil and soft rock. Four statistical models for predicting optimum bolt supports using a minimum solid beam thickness were established, and based on these results, a design criterion was proposed. Fhwa nhi06088 6 slope stability soils and foundations volume i 6 3 december 2006 6. They are certainly major factors in cut slope stability and in. By providing rock bolts, anchors or dowels in appropriate orientation. Robust geotechnical design of rock bolts for stability of rock slopes.
There are several types of slope failures such as plane failure, wedge failure, circular failure, toppling failure and buckling failure. Very often, particularly for excavated slopes, the limit. Abstract stability of rock slopes in many civil engineering projects involves installation of. Rock boltnail this is tensioned bar inserted into rock forming a short anchorage zone in rock so that an unstable slope area being reinforced by tension. The effect of installation angle of rock bolts on the stability of rock. Pdf study of effect of bolt anchorage parameters on rock slope. Rock reinforcement design relies primarily on surface mapping and logging discontinuities from borehole data to assess fracturejoint patterns and other conditions. Detailed pieziometric data at multiple locations and depths within and. Safety factor sf calculation for a slope a without tension crack b with a waterfilled tension crack.
Design parameters of nonprestressed rock anchoring system in projects with different types should be determined by formation conditions and stability analysis. How do friction and cohesion work together to stabilize slopes. Reliability analysis of anchored rock slopes against planar failure anmol nagpal, former m. Symbol parameter dimensions f factor of safety against sliding along sheet joint calculated h height of the overall slope or of each bench 60 m or 20 m respectively. Designing, constructing and monitoring of slopes in rock mass in. Designing, constructing and monitoring of slopes in rock. Worked examples presented at the workshop eurocode 7. Pdf robust geotechnical design of rock bolts for stability of rock.
Pdf stability analysis of a rock slope in himalayas. Given the size of blocks and the maximum lenght for the bolt. The criterion now incorporates both intact rock and discontinuities, such as joints, characterized by the geological strength index gsi, into a system designed to estimate the mechanical behaviour of typical rock masses encountered in tunnels, slopes and foundations. At cut design, stability analysis for the failure through the rock mass, plane and. Engineering design of rock slope reinforcement based on. The impact of the number of strata layers within bolting range and pretension applied to bolts upon the stability of an opening was investigated using flac model. Rockbolting design is indeed mainly based on experience and it appears that rockbolting design is simply a business of selection of rockbolt types and the determination of bolt length and spacing, but, one essentially uses, either explicitly or implicitly, a methodology.
Rockbolt is the most widely used support element in support systems in underground mines and civil tunnels. The fully grouted bolt is a convenient, effective, and economic technology for slope reinforcement. This program is used to perform slope stability analysis embankments, earth cuts, anchored retaining structures, mse walls, etc. Tensioned anchors also known as rock bolts are used on rock masses that. Deterministic and probabilistic rock slope stability analyses will be taught by professor p. Erik eberhardt university of british columbia geological engineeringearth and ocean sciences, ubc, 6339 stores rd. Water control is generally maintained through installation of surface and subsurface drainage devices within. The diagram shows the values of srf for the slope with dip of 75 degrees and different spacing of rock bolts that were installed at different angles the diagrams in figs. The rocks present at the bridge site are heavily jointed.
Gravitational force force due to seepage water erosion of the surface of slopes due to flowing water the sudden lowering of water adjacent to a slope. Rock slope design guide ohio department of transportation. Fundamentals of slope design 2 fundamentals of slope design e. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. This tension is then locked in by the latersetting grout cartridges and the resulting installation is a fully tensioned, fully grouted rockbolt. Rockbolts and cables 6 30 minutes, the bolt can be tensioned within two or three minutes of installation after the fast anchor resin has set. The effect of spacing of rock bolts on the stability of.
Water in a slope may come from two primary sources. Geotechnical design dublin, 14 june, 20 support to the implementation, harmonization and further development of the eurocodes. Engineering design of rock slope reinforcement based on nonlinear joint strength model. The slip surface is considered as circular bishop, felleniuspetterson, janbu, morgensternprice or spencer methods or polygonal sarma, janbu, morgensternprice or spencer methods. How does the slope angle play a role in slope stability.
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