Leo Baldwin
Structural
Need some 'simple/basic' help here...
An engineer in Greece wants to introduce load-bearing beams (14"Wx24"D) on a small 28'x50' residential 2 story project.
Saying that the 1-way ribbed concrete floor cannot handle the seismic zone III (max. horizontal acceleration A max = 0.25g)
However, this floor has been used over all California/Oregon, for spans over 33' and this is 28'.
The slab is 3.5" thick, ribs are 4.75"Wx10.5D spaced @ 24" o/c. With bottom bars being 2-#7 or even 2-#8 the span is fine.
0.25g is not a lot...
The structural engineer (being used to post and beam design (large hollow bricks)) suggested to support the floor with these beams as he doubts that floor can be engineered to meet the zone III requirements.
Here's something else - Suppose I ask the engineer to design the walls with solid concrete (6" core 3000 psi) - would the need for 14"x24" beams go away? Or are the beams simply there because the floor is so thin? Please help.
An engineer in Greece wants to introduce load-bearing beams (14"Wx24"D) on a small 28'x50' residential 2 story project.
Saying that the 1-way ribbed concrete floor cannot handle the seismic zone III (max. horizontal acceleration A max = 0.25g)
However, this floor has been used over all California/Oregon, for spans over 33' and this is 28'.
The slab is 3.5" thick, ribs are 4.75"Wx10.5D spaced @ 24" o/c. With bottom bars being 2-#7 or even 2-#8 the span is fine.
0.25g is not a lot...
The structural engineer (being used to post and beam design (large hollow bricks)) suggested to support the floor with these beams as he doubts that floor can be engineered to meet the zone III requirements.
Here's something else - Suppose I ask the engineer to design the walls with solid concrete (6" core 3000 psi) - would the need for 14"x24" beams go away? Or are the beams simply there because the floor is so thin? Please help.
