Multi level basement wall

[fd1978]

I am working on a building that has a 4 level basement. The building is located in a high seismic zone and the geotech engineer has recommended a seismic load to be applied at 60% of the wall height. Should I use the total height of the wall or the floor-to-floor height?

Also, the software that I have will only handle single level basement wall design. Could anyone please recommend a software that will do multi level basement wall design?

 

[hokie66]

If the geotechnical engineer has recommended a seismic loading pattern, he should define it. Ask him.

As for multi-level basements, your loading is likely to be trapezoidal over the height of fill. Don't see why you can't just design it as a one way slab with the load cases as recommended by the geotechnical.

There really should be no need for software other than maybe a beam program in designing basement walls. Apply the loads, calculate the bending moments and shears, and design accordingly.

Pay special attention also to horizontal reinforcement to control restraint cracking.

 

[msquared48]

Unless your floor diaphragms are concrete, I do not think you want to throw the lateral soil loads of a four story basement into the building structure. You may need to think about some form of wall restraint like soldier pile and tiebacks.

Mike McCann
McCann Engineering