lift load

Hi,
I'm designing the foundation for a 2-car lift. Reaction loads R1 & R2 are 8200kg & 4500kg (R2 on the lift entry side) on the top of the lift & the impact loads P1 & P2 of 9800kg & 7600kg at the bottom of the lift.
Should I add up the impact & static load or just cosider impact load alone for load transfering to the foundation?

 

[ishvaaag]

A clarification is required on what the loads are, and this should be given in the process of gaining the values you describe. The impact effects use to be accounted through an impact factor that multiplies the basic static load. If so has made in your case, the bottom factored loads could be used directly to dimension the foundation. Note that typically non-factored or service level are used to dimiension the foundation, and except you want to pass your loads to the soil loads in the range of those that you describe require a ridiculous small foundation. Use typically a mat of the whole plan as foundation.

 

[benishak]

It's worth to identify what type of lift system you have ie a hydraulic one or normal pulley type. In both cases, the centroidal resultant force should be checked against footing center of gravity to avoid soil tension or rather having eccentric footing. If it's a hydraulic one, then verify with the manufacturer to check pit depth.

Thank