Has anyone seen an approval for a HSS Moment Frame connections as a SMRF? I have seen the standard RBS, WUF-W, WUF-B, etc, etc (although they are not all approved), but I have not seen any discussion of HSS as Special Moment Resisting Frames. Any input?
Thank you,
SeattleMike
Hello fellow Structural Engineers,
This may be a dumb point, but 6x6 - W1.4xW1.4 WWM comes up woely short of the ACI requirement of 0.0018.... in a 4" slab, WWM = 0.28 sq in/ft, but ACI requires 0.0018*4*12 = 0.0864 sq in/ft.
what's that all about?
Why does standard Welded Wire Mesh that we...
Hello fellow structural engineers,
Several years ago, I think I went to seminar on the UBC transition to IBC, and it mentioned this problem with Masonry, and I am just now running into it:
IN the WSD design method:
IBC has an equation for lap splices that overrides ACI 530, and for #5 bars...
Hello fellow Structural Engineers,
I am a licenced and practicing structural engineer in Washington, and I am doing research into lawsuits that have been brought against us for damage due to earthquakes or hurricanes. However, I am having trouble finding any cases where this has happened...
Windows are typically designed for a failure rate of 8 or 9 in 1000, that is less than 1%.
However, in modern buildings that are complete curtain walls, each side might have several thousand 2x4 windows in the curtain wall... and typically a few fail... so, that would make one think that ANY...
Hello Structural Engineers,
Question on the Florida Building Code, in the Wind-Debris Zone (but NOT the High-Velocity Hurricane Zone):
Our firm is designing a 7-story office space-parking building in downtown Cape Coral, Florida. Still waiting to hear if it's exposure B or C.
The architect...
Hello fellow Structural Engineers,
I have a house project in which the contractor missed building a major shear wall (1/2" plywood x 12" long x 3 stories high.)
So, one idea we have is to sheath the curved (in plan) wall that is the curved stair outside wall. It is the only full height...
Hello Engineers,
So, while steel roof deck is not allowed to count as continuous ties for sub-diapragms across the length of the building, it is my understanding that metal deck is typically considered adequate for tension and compression bracing/anchorage of the sub-diaphragm whereas on a wood...
HELP!!! haha, sorry, I couldn't resist.
Hello my good Structural Engineers,
Happy Holidays to you all.
I have a question that has bothered me for some time:
Typically house foundations have perpendicular walls that help with overturning, even Z shaped walls, and they have point loads...
Hello,
QUESTION:
I am attempting to design a curved steel staircase, but I am unsure of how to calculate the effect of the curve.
GIVEN:
The inside radius is 15'-9" and the outside radius is 19'-7".
The stair stringers span approximate 16.5'.
The strair treads are 14 GA steel and 11" long...
Hello fellow Structural Engineers,
Has anyone done research on the costs of Base Isolation of buildings? With the savings of reducing base shears by a factor of 3x or 10x, or the idea of keeping the remainder of the building elastic, I was wondering if there could be an overall savings in...
SLENDER Concrete Shear Wall analysis
Hi All,
So, typically, I've seen engineers run ETABS linear(elastic) dynamic analysis of Concrete Shear Walls, with ACI effective stiffnesses for cracked and uncracked sections.
On smaller buildings, I've seen engineers just run RISA wall panels elements...
Hi All,
So, typically, I've seen engineers run ETABS linear(elastic) dynamic analysis of Concrete Shear Walls, with ACI effective stiffnesses for cracked and uncracked sections.
On smaller buildings, I've seen engineers just run RISA wall panels elements, discretized to get tensile forces for...
There has been some talk that the 1/3 increase for masonry is going away in the IBC 2006. But it's still in the IBC 2003, right? 2.1.2.3 of the ACI 530-02/ASCE 5-02 seems to allow the 1/3 stress increase, which can be used with the ALTERNATIVE basic load combinations of the IBC 2003.
What do...
Banded tendons in PT slab design are meant to support a wide area, so it seems live load reduction per IBC could be acceptable?
Is that correct? What do you think?
Hello fellow engineers,
My office is reviewing a PT slab for another engineering office.
The project is townhomes and a courtyard over a PT deck with parking below.
The other engineering office is only using 3/4" cover instread of 1" (for weather exposure). I assume they are going to justify...
Hello fellow engineers,
I have not designed a post-tensioned slab before although I do have several design examples and some office help.
For Post-Tensioned concrete slabs with banded tendons, what is the effective width for the slab design? My slab is 10' thick, and the trib load is 20'...
Hello fellow engineers,
Question 1 of 2:
Our ACI code specifies a minimum 1% steel in columns so that we don't have catastrophic failures such as in the Pakistan earthquake last year. I believe the minimum 1% is in there to provide 3 fold protection:
1) Ductility in the ends and joints...
