Question:
When checking the member strength of web stiffeners acting in combination with a length of a member’s web, the computed active length of the web is given by 25*twc (25 x the thickness of the column’s web). Ref: Salmon & Johnson p.895 and LRFD-K1.8
Why isn’t the full beam depth D...
I am looking for suggestions on how to repair two "blemishes" / rust spots in a residential pool slab. One adjacent to the floor drain, the other is in the middle of the pool bottom slab. It looks like they are the result of pin-holes in the concrete letting water get to the rebar. I'm...
I have a floor slab to design to support storage rack W6 posts with a 14 kip load. The PCA Charts do not have a wide enough range for the X and Y distances between posts to cover my situation (X = short distance = 138" and Y = long distance = 240"). I'm wondering what others do when they run...
I am looking for a reasonably priced, intuitive software package to manage multiple projects (5-10) as an Owner's representative. The main functions would be to organize and manage contracts, change orders, drawings, drawing changes, submittals, meeting notes, etc. While scheduling might be a...
I'm working on a remodeling project for an 1955 heavy industrial building. I have the original drawings! There is a note on one of the wall sections that calls out "H.H. Robertson 2Hr. Firewall" as the wall panels. The section does not call out a wall thickness, but it looks to be 3" or 4". Does...
I’m designing some aluminum extrusions for use as the structural framework for large horizontal sliding doors. As most of you know, trying to find the correct allowable stresses to use for aluminum extrusions is no simple task because the allowable stresses are dependent upon the Alloy, the...
I have run across a structural floor system I have not seen before and I'm looking for design information. I have the architectural drawings dated 1953, but no structural drawings. The system is composed of 10" deep "light" steel joist labeled #102SJ with what looks like a light gage steel...
A concrete sub-contractor poured a structural deck over an accelerator room scheduled to house radiation equipment for cancer treatment. The deck is approximately 3’ thick with an integral concrete beam that is 6’ deep. Based on 3 day and 7 day cylinder breaks, both of which were higher than the...
In general, for the same local aggregates & sand, is the unit weight of the concrete increased by going from 1" stone to a pea gravel size stone in the mix?
We have a project that requires 4,500 psi @ 148 pcf concrete and the "standard mix" designs are producing 145 pcf concrete at the site...
I've thought about this question a few times over the years and I'm wondering what you fellows think about it.
Many years ago, during the construction of a local precast concrete warehouse, a dispute arose, while I was not involved in it (really I wasn't - honest!) here is the gist of it: The...
I'm trying find a way to satisfy the deflection requirement for this section of the code for an EXISTING installation. The code section requires that the differential deflection between two adjacent glass panels not exceed the thickness of the glass panel under a horizontal loading of 50 plf...
Anyone have an idea or reference as to the amount of chert allowed in a naturally occurring aggregate for concrete? I believe state DOT's limit chert to 5% of the aggregate for highway construction, true? My question actually has to do with architectural concrete flat work.
“The highest attainment in design is a simplicity approaching functional perfection.”
- Linton E. Grinter, Ph.D., C.E.
“Nothing discredits the usefulness of theory as a practical design tool so much as the use of theoretical toys. It is often true that theory tends to become an end in...
I thought the guys that walk the steel on high rise buildings were nuts, but this takes the cake! I'm glad there are people willing to do this, but not even downing a lot of adult beverages would I have the courage(?) to do this!
IF YOU HAVE ANY VERTIGO PROBLEMS ALSO DON'T ATTEMPT TO WATCH...
In checking some shop drawings I noticed that the outside detailer selected beam web stiffener thicknesses to match the beam's flange thickness. When checking the thickness required by calculation, the thickness I come up 5/8" vs his 7/8" as an example. I'm wondering if the detailer is just...
It’s time for me to get a new computer for work. I would like some recommendations on the amount of RAM and a video card; speed and memory? AutoCAD Light, Enercalc, and Bentley’s Ram Advanse software are my most used software packages.
I have a project which will have a large operable partition, track supported at the top with a cam-lock friction sole at the bottom. When open the wall will be 80' wide and 30' tall; when closed the panels (4'x 30') slide along the track and will rotate 90 deg. to stack in a pocket at one side...
I gave some thought to posting this in the Reliability Forum or the Structural Forum or one of the Mechanical Engineering Forums, but this is probably the right place. If you haven't seen this demonstration of a new table saw design, you are in for a real surprise.... take a look at this and...
Just wondering what connection design software my fellow engineers are using?
I've written my own spreadsheets for the little of this I normally do, but I'm looking at a much larger project where I would be doing only the connection calculations for a fabricator. I'm thinking about investing...
I like using the City Blueprint font in AutoCAD, it looks hand printed, more traditional and less sterile than many other choices. The problem is it can be hard to read. Is it possible to get it in BOLD type or change to heavier line weights?
