In designing isolated footing using Eurocode, Direct Method under Design Approach 1, 2 or 3 may be adopted.
Under Design Approaches 1, 2 or 3, bearing capacity checks are carried out for each limit state, i.e ULS and SLS.
At the ULS, the bearing resistance of the soil should be checked using partial factors on the soil properties as well as on the loads.
At the SLS, the settlement of the foundations is calculated and checked against permissible limits.
Question 1:
In Staad.Foundation.Advanced (SFA) under the Isolated Footing job module, the analysis and design of footing is always based on rigid analysis method (triangular pressure distribution at base), hence is only suitable for checking the SLS limit state.
The Isolated Footing job module does not do analysis and design for ULS limit state (rectangular pressure distribution at base). Hence, ULS soil bearing resistance check can't be conducted in SFA. Please advise.
Question 2:
In SFA, sliding and overturning check always utilizes servicability SLS load cases. However, as per EC7, sliding and overturning shall be checked against ULS condition and that partial safety factors need to be applied to the loads. Hence, sliding and overturning check in SFA is not in proper compliance with EC7. Please advise.
Question 3:
SFA Isolated Footing job module only does footing shear and flexural reinforcement design in accordance with EC2, but lack / no functions to check bearing capacity in accordance with EC7. Please advise.