Slope stability analysis slope w is the leading slope stability software for soil and rock slopes. Incorporation of the spectral pseudostatic procedure into. Comparative study of soil slopes using static and pseudostatic approaches written by parbin sultana, suman hazari published on 20140526 download full article with reference data and citations. I am grateful for the financial support provided by the offshore. C department of the army, office of the chief of engineers, 1982. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. 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. Pseudostatic slope stability analysis the pseudostatic slope stability analysis is based on the evaluation of the limit equilibrium in which the inertial effects of the earthquake are represented as horizontal and vertical forces. So a pseudostatic model would actually be a dynamic model that mimics a static system. Table 2 static and pseudostatic slope stability analysis description of analysis figure no. Mobislope brings fully featured slope stability analysis to the ipad. However, the use of the pseudostatic method in these soils is also problematic as clayey slopes generally fail in pseudostatic stability analyses i. The term landslide refers to a situation of instability affecting natural slopes and involving large. A seismic slope stability probabilistic model based on.
The effects of different parameters on slopes stability are shown by performing several analyses. B4 pseudostatic slope stability analysis to determine yield acceleration b5 permanent displacement calculations attachment c results of static and seismic slope stability analyses crosssection across phase iv c1 results of static slope stability analysis c2 results of seismic slope stability analysis. Rock slope engineering civil engineering i am menglim. The evaluation of seismic slope stability and ensuring serviceability of slope after earthquake is very important. Two example analyses were comparatively performed to verify the reliability and rationality of the pseudostatic method. At present, there are roughly four methods for seismic stability analysis of slopes. A comparative study of pseudostatic slope stability analysis using. From analysis of the stability of the downstream slope before the earthquake, the s. Terzaghi 1950 first applied a pseudostatic approach to analyze seismic slope stability. A computer program was developed to validate manual calculations and facilitate calculation work. Multistage pseudostatic analysis geoslope international. A comparative study of pseudostatic slope stability. Michalowski, stability assessment of slopes with cracks using limit analysis, canadian geotechnical journal, 20, 50, 10, 1011crossref. This approach uses a single, monotonicallyapplied horizontal andor vertical acceleration to represent earthquake loading.
If no important buildings are present in the sliding areas, a pseudostatic method combined with the limit equilibrium method lem or finite element method fem can be used to assess the seismic slope stability. Rather, our intent is to illustrate the principal steps taken in the development of commonly used, rational screen procedures, and the conditions for which these procedures are intended to be applicable. Slope stability analysis under seismic load by vector sum. This pseudostatic force represents the destabilizing effects of the earthquakeshaking. Further details about the limit equilibrium theory, search procedures and slice development are. Two options are available for calculating the undrained strengths prior to the application of the seismic forces. Framework to assess pseudostatic approach for seismic. 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. The analysis is performed at both static and pseudostatic modes. Unlike the previous studies, the formulation presented in this paper is able to analyse any type of the sliding surface. Bray 2011 pseudostatic slope stability procedure paper aws.
Pseudostatic seismic analysis of reinforced soil slopes. Fig 2 force diagram of soil above failure surface in pseudo static slope stability analysis. The pseudostatic ps approach is still the most common procedure employed for standard, seismic slope stability evaluation. A summary of the slope stability analyses of the cross sections analyzed is presented below. Many researchers have developed new calculation methods to analyze seismic slope stability problems, but the conventional pseudostatic method is still widely. Forcebased pseudostatic methods versus displacem ent based methods for slope stability analysis 253 the permanent displacement d induced by an acceleration time history can be expressed as a function of the ratio kykmax. Comparative study of soil slopes using static and pseudo. 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. Some procedures are available for the analysis of rapid drawdown, but these suffer from several shortcomings and, furthermore, are not applicable to. Finally, the analyses performed by this method are compared with the ones obtained by finite difference method fdm.
Slope stability analysis for undrained loading conditions. Rational pseudostatic stability analysis of embankments. This approach is a generalization of common limiting equilibrium le slope stability analysis in which earthquake effects are represented by an equivalent static force, the magnitude of which is a product of a seismic coefficient k and the weight of. Seismic coefficients for pseudostatic slope analysis. In this case, since it is kh,max kh,eq kh,c permanent displacements will occur figure 3a and evaluation of slope stability requires a comparison of. Reliability analysis of slope stability using monte carlo. Origin of the seismic coefficient approach terzaghi 1950 severe 0. Reliability analysis of slope stability has attracted considerable research attention in the past few decades 610. Second, only peak ground acceleration pga is considered, and the effects of shaking frequency and.
Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. In this paper, two drawbacks of the traditional pseudostatic method vertical slice method in the slope stability evaluation have been studied. Improvement of pseudostatic method for slope stability. Gb 5033020 recommends seismic stability analysis for permanent slopes in earthquake zones where the basic intensity is 7 or greater.
In this paper, the horizontal slice method hsm is employed to examine the stability of reinforced soil slopes. Slope stability analysis, including the creation and saving of screen plots, 6. Shouldnt the appropriate term be a pseudodynamic model. Data tables for establishing the slope geometry, and assigning soil properties and boundary loads, 4. Pdf framework to assess the pseudostatic approach for the.
These are the socalled pseudostatic forces, which are assumed to be. In fact, the seismic load is equivalent to invariably horizontal and vertical forces, and the problem of seismic stability of slopes is simpli. Model complex geometries, pore pressure conditions, tension cracks, surcharge loads, and seismic loading. However, the use of the pseudostatic method in these soils is also problematic as clayey slopes are always failed in pseudostatic stability analyses i. Analyses of seismic slope stability problems using limit equilibrium methods in which the inertia forces due to earthquake shaking are represented by a constant horizontal force equal to the weight of the potential sliding mass multiplied by a coefficient are commonly referred to as pseudostatic analyses. Variation of factor of safety with respect to static forces and. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. Pdf numerical methods in analysis of slope stability. Pdf this study compiles the results of seismic stability analysis of an infinite slope from three methodologies, i. Slope stability evaluations by limit equilibrium and. The current state of art for limit equilibrium analysis of slope stability problems lacks a satisfactory procedure for stability evaluation under general, rapid undrained loading conditions. Slopew can effectively analyze both simple and complex problems for a variety of slip surface shapes, porewater pressure conditions, soil properties, and loading conditions. Finite element fe pseudostatic analysis can provide a good compromise between.
Detailed pieziometric data at multiple locations and depths within and. Robert pyke selection of seismic coefficients for use in pseudostatic slope stability analysis, 2011. To me pseudo means not actually, but having the appearance of, i. Slope stability analyses for materials with a nonlinear.
Stability charts for pseudostatic slope stability analysis. Macslope slope stability analysis for the mac os desktop. 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. 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. 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. The next step in the ongoing development of the spectral pseudostatic producer is to implement it into one of. 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. Keywords slope stability, slope, displacement, performance, seismic coefficients 1. Reliability of slope stability is frequently measured by reliability index, and slope failure probability, p f, which is defined as the probability that the minimum. In addition, the analyses were performed for pore pressure distributions by seepage analyses and pseudo.
Limitations of pseudo static methods in stability analysis. Appendix b shows plots of the yield acceleration values that have been obtained from pseudostatic analysis assuming ho mogeneous soil profile with c and. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. Although the vertical acceleration can be included in a pseudostatic analysis, it is rarely used in practice, as explained below. Slope w can effectively analyze both simple and complex problems for a variety of slip surface shapes, porewater pressure conditions, soil properties, and loading conditions. Pdf performancebased slope stability analysis and the pseudo. Slope stability evaluations by limit equilibrium and finite element methods trondheim, april 2006 thesis submitted to the faculty of engineering science and technology, norwegian university of science and technology in partial fulfilments of the requirements for the degree of philosophiae doctor in civil engineering. Slope stability analysis by shear strength reduction method.
Join researchgate to find the people and research you need to help. A staged pseudostatic analysis can be completed to give consideration to this scenario. Mobislope slope stability analysis for engineers on the go. Earthquakeinduced displacement rapidly decreases with increasing kykmax. Stagedthepseudostaticbaseanalysis a staged pseudostatic analysis involves the completion of two stability analyses for every single slip. A comparative study of pseudostatic slope stability analysis using different design codes xinguang yang a, endi zhai b, yuan wang c, zhongbo hu d a central research institute of building and construction co. In these methods, the pseudostatic method is the simplest at the earliest applications 4.