In this paper, two drawbacks of the traditional pseudostatic method vertical slice method in the slope stability evaluation have been studied. Plaxis 3d is a finite element package intendedfor threedimensional analysis of deformation and stability ingeotechnical engineering. Comparison of the pseudostatic and dynamic behaviour of. Seismic analysis of reinforced earth wall along with soil. On the plaxis knowledge base support section, we have made command log files. Tool to calculate structural forces from cylindrical volumes, i. A numerical simulation on the dynamic response of mse wall. I would like to apply a seismic coefficient to inertia such that lateral force is a fraction of g, and not an acceleration function similar to response spectra or time history.
Choose options for limit equilibrium or finite element stress methods, porewater pressures, trial slip surfaces, tension cracks, probabilistic and sensitivity methods, pseudostatic loading, partial factors, convergence criteria, and more. The static equilibrium of a continuum can be formulated as. A 2d finite element model for the maximum section of the dam and soil profile including bedrock was developed by plaxis software 11 for the dynamic analysis. It is very easy to execute such log files either by 1 copying and pasting or 2 save the command log file and open it in the commands runner option 1. Pdf analysis of retaining wall in static and seismic. Shotcrete model vip rigid body tool with translation and rotation conditions applied from single arbitrary reference point. Fem is better for the static problem meanwhile the fdm. The analysis is relatively simple and straightforward. Prediction of the seismic behavior of an underground. A staged pseudostatic analysis involves the completion of two stability analyses for every single slip surface i. Improvement of pseudostatic method for slope stability. Dynamic analyses were conducted to simulate the earthquakeinduced deformations of the dams using the computer program plaxis code. We will use this information to keep you updated about the products and services requested for administration and sales analysis. This work is downloaded from delft university of technology.
Dynamic response of cantilever retaining walls considering. Seismic analysis of reinforced earth wall along with soil structure. Indeed, its similarity to the static limit equilibrium analyses routinely conducted by geotechnical engineers makes its computations easy to understand and perform. For dynamic analysis a calibrated plaxis 2d model of the reference case anchored sheet pile quay wall is created. Plaxis 3d is a finite element package intended for threedimensional analysis of deformation and stability in geotechnical engineering. Nevertheless, the straightforward pseudostatic analyses need a careful evaluation of the surface. Pseudo static acceleration and model size slope stability. In plaxis 2d and plaxis 3d a pseudo static acceleration can be defined per phase in the model conditions pseudostatic option in the. Model solutions for performancebased seismic analysis of an. Researchers have also used the finiteelement method to analyze retaining systems and have developed computer software. This update pack for plaxis 3d ae offers bug fixes and some improved functionality. The seismic slope stability can be ascertained by evaluating factor of safety using pseudostatic or pseudodynamic approaches and force based equilibrium method. Delft university of technology model solutions for. The sequential seismic loading in the plaxis 2d model follows the same.
In this study plain strain numerical analysis is performed using plaxis dynamic program where prescribed displacement is applied at the bottom boundary of the. We do not pass your details to third parties to use. I have rarely use abaqus so can not tell much about that. Plaxis 2d dynamics is an addon module to plaxis 2d. These results are in line with other studies that use added masses methods for hydrodynamic pressures. Traditionally, geotechnical engineers have assessed the seismic stability of slopes by pseudostatic analysis where the inertial force caused by. Plaxis 3d is a powerful and user friendly finite element package intended for threedimensional analysis of deformation and stability in geotechnical engineering and rock mechanics. In the pseudostatic analysis, the peak ground acceleration is converted into a pseudostatic inertia force and applied as a horizontal incremental gravity load. When using numerical modeling software such as plaxis 2d to model slope stability or a tall. Pseudostatic stability analysis that uses a mechanism at a. A more advanced alternative is the performancebased design pbd method, which evaluates permanent deformations and amounts of repairable.
Or, alternately one can use makdisi and seed 1978, which. Determination of stable cut and fill slopes assessment of overall stability. Abstractconventional seismic designs of quay walls in ports are mostly based on pseudostatic analysis. The pseudo static analysis is the summation of a permanent body force representing the earthquake shaking with a static finite element analysis 16. This example shows a building subjected to an earthquake and the usage of free vibration to determine the natural frequency. I need to run a pseudostatic lateral analysis in which structural inertia represents the earthquake load. Pseudostatic and dynamic nonlinear finite element analyses have been performed to assess the dynamic behaviour of gravity retaining walls subjected to horizontal earthquake loading.
In the dynamic analysis, an actual measured earthquake acceleration time history has been scaled to provide peak ground acceleration values of 0. When using numerical modeling software such as plaxis 2d to model slope stability or a tall retaining wall with seismic loads, a quick method is to use the pseudo static acceleration as opposed to several time histories and full dynamic analysis. Second, only peak ground acceleration pga is considered, and the effects of shaking. Other wall displacements calculated using pseudostatic methods for other earthquakes are shown in fig. Tutorial examples or validation and verification cases. Comparison between numerical, pseudostatic and permissible sliding with vertical back surface. The evaluation of seismic slope stability and ensuring serviceability of slope after earthquake is very important. That in turn raises the question of what seismic coefficient should be used in a pseudostatic analysis but a robust answer to that is provided in pyke 1991, which drew on the work of makdisi and seed 1978. It is equipped with features to deal with various aspects of complex geotechnical structures and construction processes using robust and theoretically sound computational procedures. Fe plaxis analyses, the le mpm analyses may estimate 5 14% higher. How to use command log files plaxis soilvision wiki. The input procedures enable the enhanced output facilities provide a detailed.
Plaxis program, however for more advanced seismic analysis the dynamics module is necessary. The results of the parametric analyses are reported in terms of pertinent normalized parameters, to provide a general framework for the assessment of wallsoil dynamic interaction under strong seismic excitation. Pseudostatic lateral analysis technical knowledge base. However, for more advanced seismic analysis, choose the plaxis 2d dynamics module. For more information please look at our privacy statement. Lt is the transpose of a differential operator, defined as. Pseudo static analysis was performed for the case study. The effects of vibrations have to be calculated with a dynamics analysis when the frequency of the dynamic load is in the order or higher than the natural frequency of the medium.
Pdf pseudostatic and dynamic analyses of tunnels in. It produces a scalar index of stability the factor of safety that is analogous to that produced by static stability analyses. Prediction of the seismic behavior of an underground railway station. Lowfrequency vibrations can normally be calculated with a pseudostatic analysis by default available in plaxis. The dynamics module of plaxis 2d allows us to perform dynamic analyses of the propagation of waves through the soil and their influence on structures. The first stage is completed without applying the seismic forces so that the effective stresses can be obtained at the base of each slice.
The pseudostatic approach mononobe 1929 and okabe 1924 and displacement approach newmark 1965 are common and classic methodologies in practical analysis and design of retaining structures, including mse walls. Plaxis software update archives page 2 of 5 plaxis. Here are some key features of plaxis 3d foundation. By activating the pseudostatic option in a phase, and specifying the acceleration value in at least one of the components, these pseudo static. Plaxis 3d dynamics module can handle more advanced seismic analysis than what is available by default in plaxis and can accurately calculate the effects of vibrations with a dynamics analysis when the frequency of the dynamic load is higher than the natural frequency of the medium. Rs3 is a 3d finite element analysis program that can be used for a wide range of applications in both rock and soil, such as underground excavations, sequenced tunneling, surface excavations, slope stability, seepage analysis, consolidation analysis, and much more. Once the model was defined to represent the layered construction technique, then it was modified for dynamic loading conditions. The retaining wall with backfill material was analysed with inclusion of. Slope stability evaluations by limit equilibrium and finite. Plaxis 3d dynamics module can handle more advanced seismic analysis than what is available by default in plaxis and can accurately calculate the effects of vibrations with a dynamics analysis when the frequency of the dynamic load is higher than. Zhang 2017 moving from 2d to a 3d unsaturated slope stability analysis panamunsat, dallas, texas. In plaxis 2d and plaxis 3d a pseudo static acceleration can be defined per phase in the model conditions pseudostatic option in the model explorer figure 1.
Another important feature in sheet pile design is the assessment of the geotechnical overall stability. In the output program the equivalent force arrow on your plots can now be hidden. From equation 6 and according to pseudostatic analysis, the base wall displacement 10. By activating the pseudostatic option in a phase, and specifying the acceleration value in at least one of the components, these pseudo static accelerations will be activated in the. Evaluation of the pseudostatic analyses of earth dams. Evaluation of the pseudostatic analyses of earth dams using fe. Slope stability evaluations by limit equilibrium and. Performancebased seismic analysis of an anchored sheet. An example of the use of 3d slope stability analyses. 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.
Multistage pseudostatic analysis geoslope international. Between flac and plaxis, flac base on fdm analysis meanwhile plaxis base on fem analysis so they inheritance their parent properties. Gitirana 2017 multiplane slope stability analysis of tailings dams tailings and mine waste, banff, alberta. Plaxis is used worldwide by top engineering companies and institutions in the civil and geotechnical engineering industry. The pseudostatic analysis is the summation of a permanent body force representing the earthquake shaking with a static finite element analysis 16. Rational pseudostatic stability analysis of embankments. Two options are available for calculating the undrained strengths prior to the application of the seismic forces. However, the case slopes were found to have higher fos than the. 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. Pseudostatic and pseudodynamic calculations are applied to obtain the critical acceleration.
Plaxis 3d is a finite element pack for threedimensional analysis of deformation and stability in geotechnical engineering. Rs3 3d finite element analysis for rock and soil software. Seismic displacement of gravity retaining walls kamal mohamed hafez ismail ibrahim. A staged pseudostatic analysis can be completed to give consideration to this scenario. Plaxis sometimes stylised plaxis, plane strain and axial symmetry, indicating the geometric types handled in the original code is a computer programme that performs finite element analyses fea within the realm of geotechnical engineering, including deformation, stability and water flow. Dynamic performance of the plaxis 2d model is validated with shake2000 by comparing siteresponse analysis results of both models. Plaxis 2d software accomplishes the analysis of retaining wall in static and seismic conditions. Pdf pseudostatic and dynamic analyses of tunnels in trasversal. Downloading the slope64 program the source code for slope64 is written in fortran 2003, but users are provided with the executable file slope64. It is equipped with features to deal withvarious aspects of complex geotechnical structures and constructionprocesses using robust and theoretically sound computationalprocedures.
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