Jerin Joseph's Communities Activities

Finding vertical stress inside the soil.

Jerin Joseph — Mon, 21 Mar 2022 07:15:46 GMT

Hi,

I am trying to model the loading of a steel plate placed on a dry sand bed and find the variation of the vertical stress with respect to the depth of the sand bed. I have conducted the same on the laboratory scale using a steel plate and placing pressure cells vertically below the plate as shown in the figure below.

My query is which stress should be selected from the list of stress to obtain the vertical stress that will be recorded by the pressure cells in the laboratory model?

Rinter value

Jerin Joseph — Sat, 03 Apr 2021 14:17:36 GMT

What should be Rinter value for clayey sand in case of a bored concrete pile?

MODELING THE UPLIFT LOAD BEHAVIOUR OF PLATE IN SAND

Jerin Joseph — Sun, 01 Aug 2021 05:07:44 GMT

Hello,

I am modeling a small scale uplift test which was conducted on a circular plate embedded inside a sand bed. The circular plate was of diameter 75 mm and depth of the embedment was 750 mm. The same was modeled in PLAXIS 3D using plate element and hardening soil model for the sand. The uplift was provided on the plate using the surface displacement.

I have plotted the load displacement behavior obtained from the experimental and PLAXIS. It can be seen the numerical model does not capture the failure of anchor plate (the curve gradually becoming flatter after a certain displacement as seen in the experimental curve).

Please suggest where I may have gone wrong in terms of modelling or am I missing something here.

I have also tried to provide an interface to the plate however similar result do not change much. I did note that for lower depth of plate (around 400 mm) the curve from the PLAXIS 3D did flatten after some displacement.

The numerical properties of sand were as follows

E50 = 30000, Eoed = 30000, Eur = 90000, m = 0.5, c = 0.1 Kpa, phi = 35

Validation of tension pile

Jerin Joseph — Tue, 01 Jun 2021 16:24:09 GMT

I am trying to validate a small-scale rough tension pile embedded in sand using PLAXIS 3D. I am using a volume pile with the linear elastic constitutive model for concrete and sand with MC constitutive model. The volume pile was modeled with an interface by providing an R inter value of 0.75. The attached image is the comparison of the uplift load-deformation curve of the FE model and experimental model. I have also modeled a similar tension pile using field data from literature resulting in a similar curve with the FE model giving a linear response. I have used different meshes and different constitutive models also but the response of the FE model remains somewhat the same.

Is the numerical model considered validated when we are getting such a response? Is there anything I can do to improve the model further?

EMBEDDED PILE

Jerin Joseph — Mon, 24 May 2021 03:47:09 GMT

Hello, I am doing some research on the uplift capacity of bored piles in sand. I am currently using the embedded beam option in PLAXIS 3D to simulate bored piles. However, I have a doubt whether the embedded beam can produce the same soil deformation around the bored pile as in the real field. Can the embedded beam option simulate the actual soil deformation contours as expected in the field?

MODELING OF EMBEDDED PILES

Jerin Joseph — Tue, 30 Mar 2021 14:39:45 GMT

Hi,

I am trying to validate an experimental model consisting of rough pile under uplift (tension) displacement in sand using embedded pile/beam. The model pile has diameter of 50 mm and length of 700 mm. Can anyone suggest a method to calculate the values of T skin friction, start and T skin friction end for the embedded pile. Which equation should I use should i use to arrive at T skin friction in kN/m.

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Tue, 30 Mar 2021 00:00:05 GMT

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