Analysis of slope instability factors and protection international. Sample problems to demonstrate each design procedure are included in the appendices. Results indicate that, with sustained rainfall, all slopes in the current. What are the factors that influence slope stability. Factors affecting slope stability causes of slope failure. This is defined as the ratio between the maximum height of a slope to the actual height of a slope and may be expressed as follows. Five factors influence slope stability of an embankment. In the slope failure, the arc of rupture surface meets the slope above the toe. Slope stability, triggering events, mass movement hazards. The first is by physical sliding action of the slope, from a local shallow failure or as a larger toe failure. The spencer method of slope stability analysis was used to assess the stability of the wall using the same rock mass parameters as in the udec analysis. Pdf factors affecting the stability of highway side slopes. Factors affecting slope stability in the blue nile basin.
What is the difference between a slide and a slump. Slope length, l is defined as the horizontal distance not the slope distancefrom the point of origin of overland flow to the point where the slope gradient decreases to the extent that deposition. How do friction and cohesion work together to stabilize slopes. Factors affecting slope stability in the blue nile basin authors. Analysis of influence factors of slope stability scientific. In light of major working condition types in the slopes of ancient relics, slope stability in relation to earthquakes and rainfall is analyzed using geostudio software with limit equilibrium methods. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. May 03, 2012 slope stability is affected by the following factors.
Lengthslope factor, ls the length of slope factor, l and the slope gradient factor, s are usually determined as a single value, the ls factor. When it comes to the rock mass in openpit slope, its deterioration is a nonlinear cumulative process that is. This is possible only when slope angle steep and the soil close to the toe possess high strength. To add to the above, often when short term load conditions control design, such as construction of an embankment on soft foundations, factors of safety can control lateral displacement during and immediately after construction and then with time the foundation consolidates and gains strength so that stability will improve i. Stability of slopes for excavations in different soil types.
Sensitivity analysis of factors affecting timedependent slope stability under freezethaw cycles article pdf available in mathematical problems in engineering 20186. The term slope means a portion of the natural slope whose original profile has been modified by artificial interventions relevant with respect to stability. Toe failure occurs when the soil mass of the slope above the base and below the base is mainly homogeneous. Detailed pieziometric data at multiple locations and depths within and below the slope will likely be needed. The factor of safety with respect to strength f as expressed in equation. Slope stability is ultimately determined by two factors. What are the factors that influence the slope development. Hydrological factors affecting rainfallinduced shallow. Factors affecting the stability analysis of earth dam slopes.
The parameters of the computational model in this paper are 80m, 10m, and 14m for whole height, single bench height, and bench width, respectively. Allowable degree of risk of slipping which is determined based on the existing structures and new constructed buildings around the excavation area. Slope stability is affected by many factors, their effects on the slope stability may be big or small. Sccl, india, from available geotechnical data, this paper proposes analytical and numerical models. Erosion, driven by gravity, is the inevitable response to that uplift, and various types of erosion, including mass wasting, have created slopes in the uplifted regions. The paper takes the flood discharging tunnel import. On a flat surface the force of gravity acts downward. Whenever the factor of safety of a slope is less than 1.
Lime soil stabilization method and factors affecting it. Geomorphic factors soil properties hydrology vegetation seismicity. The three stability stages provide a useful framework for understanding the causal factors of landslides and classifying them into two groups on the basis of their function. Muka the shallow groundwater, making the most of the wet slopes and rock has a high water content, thus causing a low rock strength and slopes more prone to landslides. Sensitivity analysis of factors affecting timedependent. The slope and height strongly influence the slope stability.
The water table tends to rise during wet seasons when more water infiltrates into the system, and falls during dry seasons when less water infiltrates. Time during which the excavation is required to be open. Construction activities such as excavation of slopes and filling of slopes. The first is a large scale erosion, such as a river erosion occurring at the base of a slope.
The factors influencing slope development are numerous. The newly proposed approach could be a simple but efficient tool in evaluation of the parameters affecting the stability of rock slopes and hence be useful in decision making under uncertainties. The factor of safety with respect to strength f as expressed in equation 11. Factors affecting slope stability in the blue nile basin open pdf. Hydrological factors affecting rainfallinduced shallow landslides. Factors that influence mass wasting physical geography. Rockistypicalofhighly heterogeneousmaterial,anditsinternalmicrocrackextension is closely correlated with time and the surroundings. In order to determine the slope stability of an openpit mine effectively at dorli opencast projectii dorli ocpii of ms singareni collieries company ltd. Factors affecting slope stability free download as powerpoint presentation. Pdf factors affecting the stability of highway side. Muka the shallow groundwater, making the most of the wet slopes and rock has a high water content, thus causing a low rock strength and slopes more prone to. Vegetation by providing a protective cover or influencing hydrology or affecting transport of weathered material or otherwise must form. Slope stability is affected by the following factors.
Sensitivity analysis of slope stability factorsestablishmentofslopemode. Factors affecting slope stability in open excavation. Understanding the factors affecting the stability of a performers equilibrium state. Unlimited viewing of the articlechapter pdf and any associated supplements and figures. They are certainly major factors in cut slope stability and in the stability of fill slopes involving both internal and external slope failures. Preparatory causal factors which make the slope susceptible to movement without actually initiating it and thereby tending to place the slope in a marginally stable state. How does the slope angle play a role in slope stability. Physicomechanical properties of the rock materials required for establishing these models were. Two aspects of erosion need to be considered from slope stability point of view. The influence of different contributory factors on the factor of safety of a slope varies in time due to a variety of factors. There are many factors that affect the stability of slope, which.
Physicomechanical properties of the rock materials required for establishing these models were obtained by laboratory tests conducted. 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. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. The slope stability can be analyse nowadays by using a computer program. Therefore the paper analyzed the main internal factors. Natural factors affecting slope stability include the following. Slope failure occurs when the downward movements of material due to gravity and shear stresses exceeds the shear strength. Factors affecting the stability analysis of earth dam. Factors affecting the stability of highway side slopes, case study.
Another aspect of water that affects slope stability is fluid pressure. In such scenarios, the stability of the slopes can be influenced by a range of factors including drawdown rates, slope inclination and soil properties. Analytical and numerical approach for analysis of factors. The affecting factors of slope stability based on orthogonal design. Finally, several case studies of slope stability analysis are summarized. Gravity is the force that acts everywhere on the earths surface, pulling everything in a direction toward the center of the earth. The greater the height of a slope and the slope stability kecil. These causal factors shift the slope from a marginally stable state to an actively unstable state. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of determining, relatively unambiguously, whether a. From the field monitoring to a simplified slope stability analysis author links open overlay panel m. As landslide phenomenon in chittagong city commonly takes place in the rainy season, it is worthy to find out other factors that affect slope. Lithology, tectonic characteristics and age of rocks form one set of important factors. Factors affecting on stability of waterways embankments. The results of the analysis with critical failure surfaces through the rock mass show that the wall is stable and estimates the factor of safety to be 2.
The term landslide refers to a situation of instability affecting natural slopes and involving large volumes of soil. Natural factors affecting slope stability sidle 1985. Gravity the main force responsible for mass movement is gravity. This paper investigates the effects of drawdown rate, saturated hydraulic conductivity and unsaturated shear strength of dam materials on the stability of the upstream slope of an earth dam. If the friction on a rock is stronger than gravity for a particular slope, the rock material will likely stay. Therefore, factors that tend to increase the shear stresses or decrease the shear strength increase the chances of failureof a slope. Provision of berms at intervals of low heights also helps in increasing the stability of the cover system. Factors affecting stability 141 the ability to maintain ones balance under unfavorable circumstances is recognized as one of the basic motor skills. Pdf factors affecting slope stability for triggering rainfall induced. List and describe each of them what factors affect slope stability. Such changes in the level of the water table can have effects on the factors 1 through 5 discussed above.
The second is a relatively localized erosion caused by. Along with continuous improvement of the various calculation methods, it is more important to identify the main influencing ratio factors in the process of analyzing the slope stability than to select the method of calculation. Factors affecting slope stability of landfill covers. Sensitivity analysis of slope stability factors establishmentofslopemode. Pdf sensitivity analysis of factors affecting time. The second is a relatively localized erosion caused by groundwater or surface runoff. The selected slope stability models lu and godts and slip model have been applied to the testsite slope for the period between 18th january and 9th march 2014, during which the occurrence of a shallow landslides was observed on the same slope. The shallower the slope, the less effect gravity has on pulling objects down. The paper takes the flood discharging tunnel import slope of jinchuan hydropower station for example, which is a rock slope.
The affecting factors of slope stability based on orthogonal. Jul 02, 2015 hydrological factors affecting rainfallinduced shallow landslides. The orthogonal design can make sites in the test range uniformly distributed, which is introduced to slope sensitivity analysis, and can greatly reduce the test times and gets a good test effect. Preparatory causal factors which make the slope susceptible to movement without actually initiating it and thereby tending to place the slope in a marginally stable. Samarraie and others published factors affecting slope stability analysis of homogeneous. Collect discontinuity data to obtain sufficient information. The degree of dominance or subordinance of parameters with respect to the slope system has also been interpreted probabilistically. The effect of water on cut and fill slope stability is briefly discussed below. There are several factors that influence mass wasting, but ultimately it is a battle between friction and gravity. A probabilistic systems methodology to analyze the. Provision of reinforcement in the soil above the geomembrane, and use of textured geomembrane, improves the stability of slope. Therefore, for the sake of safe construction and slope protection, it is of great significance to conduct sensitivity analysis on factors affecting slope stability. This engineer manual em provides guidance for analyzing the static stability of slopes of earth and rockfill dams, slopes of other types of embankments, excavated slopes, and natural slopes in soil and soft rock. To perform the different method of slope stability analysis used by.
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