Concentrated loads on basement retaining walls

[amccinc]

I am in the process of designing a two story residence over a basement. There are numerous large concentrated loads on the basement wall. Retaining wall calculations consider all pressures and axial loads acting on a 1 foot strip of the wall to determine vertical steel design and foundation design. With the concentrated loads included in the design, the foundation seems to be extremely over-designed. My question is as follows: Can the larger concentrated loads utilize a 45 degree projection through the longitudinal axis of the wall down to the continuous footing? This would spread the load across a larger area of the footing.

 

[UcfSE]

I would use the largest effective wall width according to either the ACI 318 (14.2.4 for 2002) for concrete or the ACI 530 (2.3.3.3 for 2002) for masonry, instead assuming a 45-degree angle. This would be the assumed length of the wall for design the footing dimensions. If you are not in the US, check out your applicable code for effective wall length at concentrated loads.

 

[miecz]

I would sum all the concentrated (dead) loads and divide by the length of the wall.