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
WillisV:
Hmm... I thought that the IBC 2003 alternate load cases defered to the material standard for 1/3 increase. AISC 341-05 (steel) strickly forbids the 1/3 increase, but NDS (wood) allows Cd = 1.6, and the MSJC-02 section 2.1.2.3 allows the 1/3 increase.
...except in MSJC-02 2.1.2 it's...
Yes, I heard the rule of thumb was 3 times the slab thicknes... I wasn't sure if there was still a minimum steel requirement... I'd never heard of one... just the better-than-nothing W1.4xW1.4 - 6X6 WWM.
Yep, looks like I will have to get my hands on IBC 2006 as soon as possible to solve all my cases. I have a lot of edge bars and 3500 psi masonry... with both 80% bars and 100% bars...
Is the 1/3 increase for Masonry still in IBC 2006 and MSJC-5, aka ACI 530-05/ASCE 5-05/TMS 402-05?
Thank you...
...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 always put in slabs not meet ACI shrinkage &...
...from equation 21-2 (page 419) are similar to the UBC's 48 db even for low strength CMU. However, when you have (2)#5 each cell, eq 21-2 gives 67*db for 1500 psi CMU and 45*db for 3500 psi CMU.
For #6 bars, one of the factors goes from 1.0 to 1.4, and things get really ridiculous....
For...
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...
well, after one failure occurs (anywhere), the increased internal pressure causes additional failures at the walls and the roof... it only takes one, then, it all goes to 'partial enclosed' and typically, roofs/ceilings, other windows, etc, get blown out.
the SEAW RSM seems to indicate high...
The 50 year reference could be just a number to give people something quantifible in their lifetime, and it may be that the Snow, Wind, and Earthquake folk just copied each other for consistency.
But nonetheless, it envokes the concept of a duration of time for which we design, although I'm sure...
My impression was that our buildings were built for a 50-year lifetime, based on the way the Wind, Earthquake, and Snow codes are written.
Also, if you do not protect the windows, you would want to design the building as "partial enclosed." See the discussion in C6.5.11.1, pg 290, of the ASCE...
By failure, I mean that they will be sucked off the building, or be blown inward. So, positive or negative pressure failure. I'm not sure which is more common:
Judging from ASCE-02, I'm guessing it's negative pressure, as the negative wall pressures are typically higher.
From SEAW-RSM...
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...
It appears that per ASCE 7-02, C6.5.9, pg 285, glazing above 60 ft needs to be protected as well: more exactly, we need to protect windows that are 30 ft or less above neighboring building roofs. C6.5.9 clarifies that any building roof within 1500 ft (horizontal) needs to be evaluated for...
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...
