I am using STAAD foundation to design foundation for a vertical vessel using the plant mode. This is the error I keep getting even though my loads are substantial.
Not sure how to correct this, please advise.
In the calculation sheet, there should be a block of information titled "Applied loads at top of pedestal - Service Stress level" and a similar one for strength level. It should look like this.
Take a look at that and see if the values look reasonable or too small. If that doesn't give you a clue, please attach the SFA file.
Still getting the same error. My fdn is a 8'sqx2' block, so no pedestal. Broke it down in the attached files as 1' mat and 1' pedestal. Thanks for your help!
We are looking into this. We will get back to you soon
Please try increasing the footing size range. Try a minimum footing size as 5ft and maximum footing size as 20ft and redesign. It should work without any errors. Also, if there are no pedestals in the model, please enter the pedestal height as zero.
In this current situation, axial load is less (as the vessel itself is lightly loaded) but the moment is high ( As wind does not depend upon the weight of vessel). Due to this reason, the stress concentration is high and pressure on soil exceeds bearing capacity. Please not that here bearing capacity value is also very less. Here following things can be followed-
1) Put the footing in a deeper lever to increase soil weight
2) Bearing capacity value can be multiplied with some factor (1.15 to 1.25 as per respective code and soil condition) for seismic and wind cases. This is possible if the soil is not sandy soil and soil consultant approves.
3) Increase the plan dimension of the footing.