Numerous discussions in thread507-438708 and thread507-161349 on this topic, initiated with IBC 2000/2003, well, a quarter century later and ICC has finally made a statement on this in IBC 2024.
1607.5 Partition loads. In office buildings and in other buildings where partition locations are...
Working on a project from 1925, concrete frame building constructed by the War Department Quartermaster Corps Construction Services at Ft Benning, GA. The 1925 concrete details use the truss (bent) bars (round in section) in conjunction with straight bars (square in section).
Q1: For a...
thread184-335672
I wanted to get back to this old thread now that it is 2016, 3 yrs after NFPA 13 (2013 print) has been out.
I'm a licensed structural engineer (SE) working with a fire protection engineer (PE) in a project located in TX (that's actually irrelevant) in Seismic Design Category...
When it comes to modeling the structure using semi-rigid diaphragms, does the eccentricity value make a difference? Since the floor diaphragm is sub-meshed into plates (given it’s modeled as semi-rigid), the seismic and/or wind forces are NOT applied to the center of mass (as is the case of the...
I’m working on a building constructed in 1908 (the historic Univ. of Chicago campus) and I have encountered a strangely called out rebar in the floor concrete T-sections:
3-1/2”x3”x7.8# T bar. (Graphically shown as a rectangular plate.)
Does anyone have any idea how to figure out the actual...
Is anyone familiar with the "BG" designation for steel shapes? I have a building constructed cca 1930 that is using this shape, 24" BG 148 in particular. I have not found such a shape in the AISC Historical Shapes Database v13.1.
Thanks!
I am designing a 20ft DIA RC tunnel liner 335' down in bedrock. The hole in the bedrock will be blasted which means the annular void between the rock and outer surface of the liner will need to be grouted. The minimum grouting pressure needs to be at least that of the external hydrostatic...
Referring to the usual references (Bowles, Coduto, Das), it is customary to neglect the passive pressure developed on the front face (toe side) of the cantilever wall’s footing. The explanation given is that “ The bottom of the footing may move slightly rearward if any overturning failure were...
I am designing a strip footing that is, due to a property line restriction, constructed as an L. The wall (stem) is propped at the top with a floor diaphragm and at the bottom with a slab on grade. In other words, the foundation system (wall + footing) cannot rotate and can only move in the...
I'm working on a rehab project (medium sized stadium) that was build around 1966 and some of the framing refers to a BL steel section (such as 18BL35). Now, from the 6th edition of AISC code, I see there are B sections (light beams) but they stop at 16x5-1/2B. From the details, the BL section...
I’m modeling a foundation mat using STAAD and I wanted to know how you model cracked section mats supported on soil springs only. For flat plate and slabs, ACI 318-05, Section 10.11.1 recommends using 0.25 I_gross, which I’d put into STAAD as 0.25*E_concrete (since deflection is normally...
I’m modeling a foundation mat using STAAD and I wanted to know how you model cracked section mats supported on soil springs only. For flat plate and slabs, ACI 318-05, Section 10.11.1 recommends using 0.25 I_gross, which I’d put into STAAD as 0.25*E_concrete (since deflection is normally...
There is a book on the ASCE website titled Finite Element Design of Concrete Structures by G A Robach. I was wondering if any of you might have purched the book and what you think of it, i.e., does it really provide "real life" applications and insights into FEA and concrete design. Thanks...
When using comments such as rotate, move, copy, etc., after selecting an object, I used to be able to see the ouline of it as I moved the mouse in order to perform the above mentioned commands. For some reason, now when I do that, I don't see the outline (only a line connecting the base point to...
I am trying to find information on the use of gypsum drywall in a shear wall system. We have a structure that was constructed using 3.5/8" metal studs at 16" centers and 5/8" gyp board each side. I would like to know how to get an rough idea about the shear resistance of such an assembly. Any...
AISC Design Guide 7 - Industrial Buildings. On page 33, for shear lugs or column embedments bearing in the direction of a free edge of the concrete, Appendix B of ACI 349-01 states that in addition to considering bearing failure in the concrete, “the concrete design shear strength for the lug...
I do not have the USGS CD that comes with IBC 2003 where one can input a lattitude and longitude (for LA, its 37.63, 118.92) and the utility will provide mapped spectral accelerations (for 0.2 sec and 1.0 sec periods) for that particular location. The maps in the IBC are rather difficult to...
I have a few double angle braces at various orientations that will require to have a plate welded along one of the sets of the legs. I have calculated all the combined sections properties (double angles plus plate) no problem. When it comes to the point of calculating of the allowable bending...
I have a retaining wall system composing of three 44 ft long walls (2 parallel and 1 perpendicular wall) that are 25 ft high and 2 feet thick. Per ACI 14.3.3, the minimum ratio of horizontal reinforcement area to gross concrete area shall be 0.0025 for bars bigger than No.5. Is this a good way...
