Problems on Soil Spring Calculator

[Anonymous]

Hello,

I am now designing a seawall structure. 

In the Robot model, I used the "foundation elasticity calculator" in thickness setting to assign the soil spring on a vertical wall supported by the reclamation soil. I expect the reclamation soil will support the caisson when there is a wave, therefore I assign a soil spring without uplift resistance.  

The problem is that I don't know how to use this calculator to calculate the soil in parallel (see picture). 

My questions are:

1. Shall I calculate the 3 layer separately in the calculator? Because the calculator can only consider soil in series.

2. What "Dimensions" shall I use for the calculation? Shall I just use the contact area of the particular soil for the calculation? Or shall I just the area of the whole wall?

Thank you.

[Rafacascudo]

I never used it , but the soil spring is perpendicular to the thickness surface . So I guess you will have to divide your wall according to the number of different soils you have and then enter the appropriate values for each wall thickness piece

[Anonymous]

Thank you for your reply.

My biggest concern is that I am not sure about what dimension should I use.

For example my soil layer 1 has 3m depth, if I input the dimension as 3m * width, then I will get a very large stiffness comparing to other layers of soil. The difference of stiffness is now mainly controlled by the soil depth while I think it cannot reflect the real case. That's why I tried to input the foundation dimension as the sum of 3 soil layers, but I do not have confidence on this method. 

I would like to know how RSA use this foundation dimension for its calculation.