slickdeals
Structural
I am reviewing another engineer's project where the soil is expansive clay. The Geotech has recommended the top 4 ft of soil to be removed and replaced with an engineered fill and provide moisture barriers. The project is in a high seismic area. The recommended bearing pressure is 3500psf.
The building is a 3 story precast building. Based on the provided base shear, I back-calculated a high floor mass which could be explained if the slab @ ground level was included in the base shear computations. My questions are:
1. If the slab is not soil supported, does it's mass have to be included in the base shear calculation for the building's lateral system and it's foundations?
2. What if the slab is soil supported, what about the seismic mass then?
My own thinking is that when it is a structural slab @ grade level, it's mass should be included. It need not be included when it's a slab-on-grade.
The other reason I am leaning on making it a soil-supported slab, is to relieve the gravity loads from the spread footings.
Thoughts?
The building is a 3 story precast building. Based on the provided base shear, I back-calculated a high floor mass which could be explained if the slab @ ground level was included in the base shear computations. My questions are:
1. If the slab is not soil supported, does it's mass have to be included in the base shear calculation for the building's lateral system and it's foundations?
2. What if the slab is soil supported, what about the seismic mass then?
My own thinking is that when it is a structural slab @ grade level, it's mass should be included. It need not be included when it's a slab-on-grade.
The other reason I am leaning on making it a soil-supported slab, is to relieve the gravity loads from the spread footings.
Thoughts?
