If you need any more help, post the issue here so I or another engineer perhaps can help you again. In your specific case, I assume the ringwall is cheaper than others tipical storage tank foundation and it was the reason your client has chosen it.
Sorry for my poor English.
Regards
Bartek22,
The first step is to determine the soil allowable bearing pressure. You can make use of any given theory of soil mechanics. For this, I suggest the slip lines method given by Sokolovski (1960.1965).
After determining the allowable soil pressure, you must find the maximum pressure...
I have not seen your third post and so I thought it was a steel column.Disregard my comments above.
Following the description of the structure you made, I understand that two of the tripod bars belong to the same plan and are linked directly to the upper beam, while the third is a cantilever...
The coefficient "k" which defines the length of buckling of the bar can be obtained through the relationship between the rigidity of the bars that join the column. First you need to assess whether the structure is moved or not. Then, simply relate the stiffness of the bars with their length...