Dear Atish Kumar Das

This link might be helpful, have a look:

https://communities.bentley.com/cfs-file/__key/communityserver-wikis-components-files/00-00-00-05-58/PLAXIS3DCE_2D00_V20.04_2D00_2_2D00_Reference.pdf

Kind Regards

Qamar Ul Islam

Really? Many a times we have modelled shallow footing using Mohr Coulomb in class and compared the results to Terzaghi's theory. It has always worked

Issue with M-C model for soil is, absence of limiting stress / strain. It works well, within elastic range, and initial plastic phase, where strains are too small. If the load is increased to a large extent, say, with a factor of 5, 10 or 20, one may still get a solution, with large displacement, without any clear failure. Unless a limiting condition for settlement / strain / stress in soil is not defined, M-C model in any software may give incorrect results. One may try this and realize. Thus, the bearing capacity may be overestimated, at large settlements. Is hardening soil method, meaning, elastic - strain hardening model, with second part of E value as some fraction of elastic modulus ? Please clarify.

Prabhakar Gundlapalli sir , it seems that for a small model analysis case the plaxis as well as lab experiment is showing a higher value, where the analysis from plaxis is identical with theoretical method of Meyerhof for the prototype scale.

Good morning Mr Gundlapalli: I think the issue here is bearing capacity and not deformation. You are right about its inability to pick strain because of the model's limitations, but Mohr Coulomb is still unbeatable in predicting the ultimate state. Its physics. Regards

Dear Atish Kumar Das,

Mohr-Coulomb model and Hardening soil model uses Mohr-Coulomb failure criterion and evaluates more or less the same failure load. Ultimate bearing capacity is failure load divided by the footing geometry.

Dear Ashish Juneja Sir even we have done this exercise in class, the evaluation of bearing capacity factors using FEM and matches well with Meyerhof solutions and is a little less than Terzhaghi's solution. Moreover, it is found that the FE solution is in between Terzhaghi's and Meyerhof's solutions.

Atish, evaluate the bearing capacity of footing using FEM and compare the FE solution with Terzhaghi's solutions too. Please refer to Table 2 in the attached paper. I hope it will be helpful.

Regards

Jitesh