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Dear sir/madam, I have a question about the critical time step and the number of substeps for a dynamic analysis model. We know that the critical time step depends on minimum element size and shear wave velocity of the soils inside the model. I have…

Dear sir/madam, I have two questions about rayleigh damping parameters. According to the manual and the other references, we know that f1=Vs/4H (fundamental frequency of the soil deposit) and f2 equals to the nearest odd integer (greater one) of the…

Dear sir/madam, I have two questions about a dynamic analysis model consists of sandy layers with (c=0). I indicated the cohesion values of the soil because i have high vertical displacements in my analysis (in the order of 20-30cm). There isn't groundwater…

Dear sir/madam, I'm working on dynamic analyses for a study. In this study, i will compare the accelerations along the depth of soil and structural forces on the piles with different: -Earthquake characteristics (PGA) -Soil parameters (Shear vave…

Hello, I am running a dynamic analysis model in Plaxis to find a vertical displacement of the pipeline in liquefiable soil, but it takes one day and is still running in 11.21 seconds. Is it normal for this kind of analysis in Plaxis? If so, anyone could…

Dear sir/madam, I have a question about the maximum frequency value (fmax) in the critical mesh size formula. There are already questions here and other platforms, but i couldn't be sure because i have seen different usages of this parameter. Should…

Dear sir/madam, I have two questions about the use of boundary conditions for an earthquake analysis according to the type of input motion: 1) If we have a rock outcrop motion and we have the deconvolved version of this input motion at the base of…

Dear sir/madam, I saw a post in the forum about the critical mesh size including a phrase like this "fmax= The frequency value at which fourier amplitude starting to decrease " and i'm a bit confused about this topic. In order to calculate the critical…

Dear sir/madam, I have two questions about the mesh size in the dynamic analysis. While we are studying on a dynamic analysis model consists of a multilayered soil profile with varying Vs values and includes some tight structural elements at the center…

Dear sir/madam, I have seen a similar question in the forum but i couldn't be sure about this topic. While we're studying on a dynamic analysis and using HS Small Model for the soil layers, should we use different Elasticity modulus values (E50, Eoed…

To perform dynamic analysis (seismic analysis) of an underground structure in Plaxis 2D, should the displacements be reset to zero, as well as the small deformations?, considering that there are previous stages or phases of construction and service (static…

Dear sir/madam, I'm working on a dynamic analysis model to check liquefaction potential of a multilayered soil profile. When i looked at the Ru values at the end of analysis and compare them with the Ru values at the intermediate steps during the earthquake…

The pore water pressure above the tunnel is observed to be positive under dynamic loading that results into negative ru, excess pore water pressure ratios. What could be the reason? kindly help me

On using PM4silt for clay and using Undrained A and for sandy soils (PM4sand) Undrained A.is it correct to use this combination while studying for liquefaction analysis?

Dear sir/madam, I have a question about UBC3D model for my dynamic analysis model: Does the "G" parameter (Elastic shear modulus, which is calculated by the kGe shear modulus factor) equal to G0=(Vs^2*(Unit weight/g))? If so, isn't this model…

Dear sir/madam, I'm working on a dynamic analysis of a multilayered soil profile improved with stone columns & piles. I have some questions regarding the parameters: While using the UBC3D model for liquefaction, we know that it overestimates the shear…

Dear sir/madam, I'm working on a dynamic analysis in a multilayered soil profile improved with stone colums & piles. I have some questions regarding this analysis: 1) To evaluate the liquefaction, i should use the dynamic with consolidation calculation…

Dear sir/madam, In the Plaxis manuals, it is stated that input motion should be factored by 0.5 if the applied input motion is rock outcrop motion and compliant base boundary is used at the bottom boundary. If we use an rock outcrop earthquke record…

Dear sir/madam, I have a simple question about the usage of rock outcrop input motion in dynamic analysis with compliant base boundary: 1) Using a line displacement with u=0.5 and input motion as its current situation 2) Scaling the input motion…

Dear sir/madam, I'm studying on a dynamic analysis model consist of nonhomogeneous soil layers improved with stone columns and rock socketed piles connected to raft foundation. I'm using two models: 1) Piles modeled with embedded beam row 2) Piles…

Dear sir/madam, I'm studying on an earthquake analysis with Plaxis 2D (with an input motion whose duration is almost 12s). While acceleration values goes around 0m/s^2 after 8s (drift correction is applied), there is a sudden and significant increase…

Dear sir/madam, Is it normal to have plastic points in the model at the end of a dynamic analysis like in the figure i shared below? I'm facing with this situation in some of the earthquake records, but not all of them. When i tried another earthquake…

Dear sir/madam, I have two questions about the usage of rayleigh damping, 1) How should we assign the rayleigh damping coefficients in layered soils? I mean that sohuld we determine the f1 and f2 values for each layer or should we determine uniform…

Dear sir/madam, I have a question about the rock outcrop motion in dynamic analysis. When the input motion is a rock outcrop motion, we should scale this motion by 0.5 for the compliant base boundary. But, i'm wondering about if we can make deconvolution…

Dear sir/madam, I have a question about maximum step number and sub step number in dynamic analysis. For example, when we give an input motion (which has a duration of 33s and time interval of 0.01s) into to model, a) Setting the maximum step number…