Plaxis 2d ground response analysis
![plaxis 2d ground response analysis plaxis 2d ground response analysis](https://cdn.datgel.com/images/plaxis/plaxis-3d2.jpg)
The soil layer consists of a lithological homogeneous clay deposit 40 m thick above thebedrock. PLAXIS 2015 | Ground response analysis in PLAXIS 2D 5Ħ Ground response analysis in PLAXIS 2D | PLAXIS 2015 Modelling boundary conditions for one-dimensional wave propagation with tieddegrees of freedom Modelling non linear behaviour of the soil using the HS small model The problem can be modelled through a soilcolumn with specific features, as described in the following sections.
![plaxis 2d ground response analysis plaxis 2d ground response analysis](https://www.geoengineer.org/storage/news/2667/featured_image/12466/featured_image.png)
This last assumptioncan be justified considering that the seismic waves, propagating from the earthquakesource through the soil, are bent by successive refractions into a nearly vertical path(according to Snell's law of refraction).
![plaxis 2d ground response analysis plaxis 2d ground response analysis](https://www.researchgate.net/profile/Saif-Alzabeebee/publication/336473259/figure/fig1/AS:817537575043073@1571927555294/Model-developed-using-PLAXIS-2D.png)
This example (with elaborated background information) concerns the one-dimensionalwave propagation analysis through a clay deposit 40 m thick above the bedrock.One-dimensional analysis can be performed when the soil layers and the bedrocksurface are horizontal and they extend to infinity, and the seismic waves coincide withshear waves propagating vertically from the underlying bedrock. The output used for the dynamic analysis of a structure representsthe average result of several ground response analyses performed for the same site byapplying a certain number of different seismic input signals (generally not less than 3),properly selected from the earthquake database and scaled at the desired value ofmaximum acceleration. The freefield surface motion is quantified in terms of amplification ratio, frequency content, peakground acceleration and spectral acceleration.įor a specific site, it is required a probabilistic study to determine all the possible seismicevents that can occur. In some cases,a 'deconvolution' analysis may be needed, in order to convert the seismic signal recordedat the outcrop rock site into the earthquake to be applied at the bedrock surface. the motion thatoccurs in the soil layers at the depth of interest (for instance, at the foundation level in thecase of a building with shallow foundation) is determined by applying the selectedearthquake at the bedrock, in the absence of any structure or excavation.
PLAXIS 2D GROUND RESPONSE ANALYSIS FREE
The site response analysis is performed in free field conditions, i.e. This means that thesystem oscillates with very high amplitudes that can cause great damages in the building.
![plaxis 2d ground response analysis plaxis 2d ground response analysis](https://communities.bentley.com/cfs-file/__key/communityserver-wikis-components-files/00-00-00-05-58/GROUND_5F00_RESPONSE_5F00_ANALYSIS_5F00_IN_5F00_CASE_5F00_OF_5F00_LINEAR_5F00_SOIL.png)
If the frequency at which the maximum amplification of theground motion occurs is close to the natural frequency of the overlying structure, thebuilding and the ground motion are in resonance with one another. Due to its filter effect, the soil depositmodifies the seismic waves by amplifying the signal at some specific frequencies anddamping it at some others. The ground responseanalysis of a soil deposit can be considered as a necessary preliminary study for thedynamic analysis of a structure, since its seismic response is influenced by the geologicaland geotechnical properties of the supporting soil. The variation of theseismic waves in terms of amplitude, duration and frequency content at any depth can beevaluated through a ground response analysis.The local soil stratigraphy, the materialproperties, the site topography, the ground water table depth and the characteristics ofthe earthquake (for example, duration, peak acceleration, frequency content) have a highinfluence on the ground response and on the modelling strategy. PLAXIS 2015 | Ground response analysis in PLAXIS 2D 3Ĥ Ground response analysis in PLAXIS 2D | PLAXIS 2015Įarthquakes propagate from the bedrock to the surface through the overlying soil deposit,which acts as a filter and modify the ground motion characteristics. BrinkgreveDelft University of Technology & PLAXIS bv, The NetherlandsĢ Geometry 72.1 General settings 72.2 Definition of soil stratigraphy and material properties 82.3 Definition of the loading condition 14Ħ Comparison of the results with EERA 336.1 Introduction to EERA 336.2 Input 346.3 Results 39