Performancebased assessment of the seismic pseudostatic. In the pseudo static approach, an equivalent seismic coefficient k is used within a conventional limit equilibrium slope stability calculation. The xstabl reference manual is intended to provide information about the interactive features that allow the user to prepare data files and perform a slope stability analysis. Comparative study of soil slopes using static and pseudo. Robert pyke selection of seismic coefficients for use in pseudo static slope stability analysis, 2011. In the foreign practice beside of pseudo static approach 1619, numerical dynamic calculations are used for evaluation of stability of natural slopes, embankments, dams and open pit edges at earthquakes by using different software packages abacus, plaxis, ansys, slope w, flack, udec, 3dec and newmarks deformational method 2027. Newmark displacement analysis is a straightforward method in which.
Multistage pseudostatic analysis geoslope international. Missouri university of science and technology scholars mine. Slope stability analysis for undrained loading conditions. If no important buildings are present in the sliding areas, a pseudo static method combined with the limit equilibrium method lem or finite element method fem can be used to assess the seismic slope stability.
Since k designates the horizontal force to be used in the stability analysis, its selection is crucial. Pdf this study compiles the results of seismic stability analysis of an infinite slope from three methodologies, i. C department of the army, office of the chief of engineers, 1982. Seismic performance of slopes in pseudo static august 2014 ijst, transactions of civil engineering, volume 38, number c2 467 1 determination of horizontal acceleration effects on slope based on.
The next six chapters of the reference manual provides details concerning the following topics. Stability and runout analysis of earthquakeinduced. Performancebased pseudostatic analysis of slopes giovanni biondi1, ernesto cascone2, sebastiano rampello3 abstract current pseudo static analysis of slopes requires the selection of an equivalent seismic coefficient keq that is demanded to globally represent the effects of the transient seismic action on the slope. Gb 5033020 recommends seismic stability analysis for permanent slopes in earthquake zones where the basic intensity is 7 or greater. Many researchers have developed new calculation methods to analyze seismic slope stability problems, but the conventional pseudostatic method is still widely. Framework to assess pseudostatic approach for seismic. Rational pseudostatic stability analysis of embankments. Therefore, a comparative study on the pseudostatic methods based on gb 5033020 and sp117 was performed. It is simple to apply and provides far more information than does pseudo.
This pseudostatic force represents the destabilizing effects of the earthquakeshaking. Geo slope international ltd, calgary, alberta, canada. Seismic slope stability international journal of computational. Extensive case studies throughout help illustrate the principles and techniques described, including a new examination of hurricane katrina failures, plus examples of soil and slope engineering from around the world. Variation of pseudostatic factor of safety with horizontal pseudostatic. Particle swarm optimization algorithm for the location of the critical noncircular failure surface in twodimensional slope stability analysis.
The present study aims at analyzing the stability of a model soil slope, comprising of an embankment and two canal bunds, at various construction stages when subjected to earthquake forces. The normal force equation is of the same form for all methods with the exception of the ordinary method. Multistage pseudostatic analysis geo slope international ltd. However, the use of the pseudo static method in these soils is also problematic as clayey slopes generally fail in pseudo static stability analyses i. Probabilistic and sensitivity geoslope international. In particular, a critical factor in pseudo static slope stability analyses is the selection of the spc, which typically is arbitrary, based on accumulated experience, regulatory design guidance, and engineering judgment. The factor of safety equations are written in the same form, recognizing whether moment and or force equilibrium is explicitly satisfied. Incorporation of the spectral pseudostatic procedure into. Probabilistic seismic slope stability analysis and design.
Methods for slope stability analysis baker, 1980 1 suggested a slip circle for determining the factor of safety using the spencer method and used the dynamic programming. 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. However, the case slopes were found to have higher fos than the recommended minimum value for such conditions. A pseudo static slope stability analysis is performed to evaluate the stability of the slope under liquefied conditions. Assessing submarine slope stability requires estimating the likelihood, extent, and impact of a. Slope stability analysis under seismic load by vector sum. At present, there are roughly four methods for seismic stability analysis of slopes. Dynamic analysis of the same have been carried out by subjecting the soil slope to. B2 results of static slope stability analysis b3 probabilistic seismic hazard based on usgs b4 pseudo static slope stability analysis to determine yield acceleration b5 permanent displacement calculations attachment c results of static and seismic slope stability. Model complex geometries, pore pressure conditions, tension cracks, surcharge loads, and seismic loading. Mobislope brings fully featured slope stability analysis to the ipad. The term slope means a portion of the natural slope whose original profile has been modified by artificial interventions relevant with respect to stability. Most design manuals and codes recommend a simple pseudostatic approach for analysis of slope stability under seismic conditions.
Table 2 static and pseudo static slope stability analysis description of analysis figure no. Macslope is an app designed to calculate and search for the critical factor of safety of earth slopes, using common methods of limit equilibrium slope stability analysis. Improvement of pseudostatic method for slope stability. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. Seismic stability of geotechnical structures like dams, embankments, solid waste landfills, etc. As stated in guidelines for evaluating and mitigating seismic hazards in california cdmg, 1997, in. However, the use of the pseudostatic method in these soils is also problematic as clayey slopes generally fail in pseudostatic stability analyses i. Macslope slope stability analysis for the mac os desktop. In this paper, two drawbacks of the traditional pseudo static method vertical slice method in the slope stability evaluation have been studied. Earthquake engineering, 1st ed prentice hall books. The term landslide refers to a situation of instability affecting natural slopes and involving large volumes of soil. Slope stability of soils is one of the major problems since the ancient times. A staged pseudostatic analysis can be completed to give consideration to this scenario. A comparative study of pseudostatic slope stability.
The influence of earthquakes on openpit slope stability. Pseudostatic analysis is one of the simplest approaches used in earthquake engineering to analyze the seismic response of soil embankments and slopes. Mobislope slope stability analysis for engineers on the go. Slope stability evaluations by limit equilibrium and. If the factor of safety fs slope stability is the essential text for the critical assessment of natural and manmade slopes.
Pseudo static analysis, because of its crude characterization of the physical process, should be used only for preliminary or screening analyses. A summary of the slope stability analyses of the cross sections analyzed is presented below. The three families of analyses for assessing seismic slope stability each have their appropriate application. Slopew can be used to complete a stability analysis with the objective being to check an ultimate limit state in accordance with various limit state design approaches such as eurocode 7, norwegian standard ns 3480, and british standard 8006. In seismic slope stability analysis, a conventional procedure, pseudostatic slope. Mobislope is an app designed to calculate and search for the critical factor of safety of earth slopes, using common methods of limit equilibrium slope stability analysis. This paper first summarizes the pseudostatic slope stability analysis method based on the two design codes and subsequently examines the factors influencing the seismic coefficient k. In earthquake engineering to analyze the seismic response of soil embankments and slopes simply adding a permanent body force representing the earthquake shaking to a static limitequilibrium analysis. The stability analysis methods satisfying only moment equilibrium may be affected by manual. The primary purpose of slope stability analysis in most engineering applications is.
Pseudo static seismic analysis of reinforced soil slopes using the horizontal. Slope stability evaluations by limit equilibrium and finite. An assessment of pseudostatic analysis methods for. Griffiths3,4 abstract deterministic seismic slope stability design charts for cohesivefrictional soils are c traditionally used by geotechnical engineers to include the effects of earthquakes on slopes. Pseudo static slope stability procedures should use parameters that are representative of the existing seismic demand and the properties of the system being evaluated 9,10. The simplest approach is pseudostatic, where the seismic forces are represented by inertia forces with constant horizontal andor vertical. First, the sliding mass is divided into vertical slices according to this method, which is irrational to some extent in the seismic design of slope. This thesis deals with slope stability evolutions carried out by commonly used limit equilibrium. Stability charts for pseudostatic slope stability analysis. The most commonly used method for analyzing seismic slope stability is the socalled pseudo static analysis technique, which was first employed by terzaghi 16 in the analysis of slopes subjected. In a pseudostatic slope stability analyss, a factor of safetyi fs is computed using a static limit equilibrium method in which a horizontal earthquakeinduced inertial force is applied to the potential sliding mass. A staged pseudo static analysis involves the completion of two stability analyses for every single slip. This study also involves seismic stability analysis of the slope using pseudostatic method.
Pdf performancebased slope stability analysis and the pseudo. Pseudo static stability analysis is a widely used limit equilibrium method that replaces the effect of dynamic earthquake loads by a constant equivalent static acceleration 2, 3. The paper compares six methods of slices commonly used for slope stability analysis. Two example analyses were comparatively performed to verify the reliability and rationality of the pseudostatic method. Two options are available for calculating the undrained strengths prior to the application of the seismic forces.
Seismic coefficients for pseudostatic slope analysis. Second, only peak ground acceleration pga is considered, and the effects of shaking frequency and. In seismic zones, pseudo static analysis is the mostcommon method in the design of retaining walls. Water table can be used for calculating pore pressure. Slope stability analysis is performed to assess the safe design of a humanmade or natural slopes e. In practice, the pseudo static analysis is relatively simple and straightforward, what makes its computations easy to understand and perform by. The focus of this geotechnical analysis and design section is to present methods and guidelines. Kinematic analysis of seismic slope stability with a discretisation. Stagedthepseudostaticbaseanalysis a staged pseudostatic analysis involves the completion of two stability analyses for every single slip.
Before presenting its conclusions, the book discusses special aspects of slope analysis, such as earthquake analysis, pseudo static analysis, dynamic analysis, and anisotropy, in addition to newmarks approach. This study also involves seismic stability analysis of the slope using pseudo static method. If slope stability is the potential of a slope to landslide, natural or manmade factors that provoke this movement of a mass of soil, rock or debris down a slope have to be well understood to predict or to prevent the problem. In earthquakeprone areas, the analysis is typically run for static conditions and pseudo static conditions, where the seismic forces from an earthquake are assumed to add static loads to the analysis. Join researchgate to find the people and research you need to help.
Rock slope engineering civil engineering i am menglim. Pseudostatic seismic analysis of reinforced soil slopes. A comparative study of pseudostatic slope stability analysis using. Stability charts for pseudostatic slope stability analysis request pdf. Macslope brings fully featured slope stability analysis to the mac os desktop. However, the choice of seismic coefficients used in the analysis can. Soil stability, slope, pseudo static, newmark block sliding. Draft 1 probabilistic seismic slope stability analysis and design by jesse burgess1, gordon a. A case history of seismic stability analysis of an adriatic coast flysch slope has been employed to evaluate the applicability and reliability of these methods. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of.