A design requires a column splice between a W6x25 and a W12x65. RISA was used to model the entire frame. For the same load case the axial forces in the members are significantly different where they join, the axial force in the W12x65 is 29kips while the axial force in W6x25 is 11kips. Is this...
We have vertical HSS being used as a supports or lateral stops for 12"ø steam pipe at various points on a pipe rack. The rack is entirely indoors in a conditioned space. Aesthetics are not a concern. Is there any need to add cap plates or end plates on the HSS?
A contractor is suggesting the use of 1ft deep, very wide concrete slab to support heavy rotating equipment. The local jurisdiction has a required frost depth 42in. Can a very heavy foundation (while still below the allowable bearing capacity of the soil) eliminate the need to go below the 42"...
I'm attempting to make a 11"x11" baseplate work below a W10x49 subjected to 20k-ft moment and 10kip shear in both directions, and a 2 kip tensile load. I'm trying to place the anchors within the column flanges. The column loading creates a "large moment" situation per AISC design guide 1 section...
If we have a steel duct plate under uniform pressure that's being reinforced/stiffened with a channel or angle how do we calculate the shear at the connection between the plate and the stiffener? I'd like to determine this force so I can check that the weld between the duct plate and stiffener...
What is a conservative K value for a partially braced frame like in the attached picture? It’s somewhere between sideway inhibited and non-inhibited. http://files.engineering.com/getfile.aspx?folder=3b6792aa-02a3-4e83-8cc1-31d212a1b315&file=Brace_Frame_K_Value.jpg
If I'm welding a 3in tall, 3/16in thick plate normal to a 3/16in plate, we're creating an inverted t-shape. How do I determine the effective width of the plate to use as my flange? I need it to determine my section properties.
We had petrography performed on a sample taken from a concrete core that came back with below expected strength. The petro results show the fly ash as being 35% of the cementing material instead of 25% as expected. The sample also showed air content slightly above ACI recommendations. I know...
The results of the 28-day tests aren't meeting the target compressive strength. We believe it's due to the strength retarding properties of fly ash in the mix. Assuming the 56-day test meets the target; are there any implications to long-term durability (40 year service life) with utilizing...
A project has 28 day breaks showing about 10% less than the target. 56-day breaks are coming in well over the 28 day target. The concrete is at about 30 days now at some locations. If the contractor places about 50% of the dead load on the structure will it affect the concrete’s curing or...
A large area new 8" thick slab will support curbs, 6" housekeeping pads, and concrete piers. Would these be poured separately because of the difficulty in forming a curb, slab, or pier on top of a wet floor? I'm used to roughing the slab and doweling in curbs, pads, etc. on an existing slab but...
What's preferable for a steel worker to place; 3/16" or 1/4" fillet weld?
We're attaching auxiliary steel to existing building steel to support some lightweight pipe (<1 kip at most support points). For our application either size is sufficient as 3/16" fillet weld provides 4.2 kips/in strength...
What is a good resource for design a slab on grade subjected to a column load? I have a column with an 18kip vertical load and soil with 150 pci subgrade modulus and I'm wondering if I can use a 12" slab. Hopefully there are tables that will eliminate the need for FEA.
Of the two resources I...
We're attaching a stainless steel screen wall underwater to an existing steel sheet pile wall. The screen is being added to protect a water intake hole cut into the sheet pile wall which happens to be very weathered. Is there any metal/material that can span between the two materials to...
Are there resources or very rough rules of thumb for the cost of placing concrete for mat foundation; pile supported or otherwise? I assume it would be priced per cubic yard. The foundation is on the order of 50' by 30' by 3'. I'm awaiting a preliminary geotech to determine what the soil bearing...
When anchoring a column baseplate to existing concrete, is there any benefit to welding the edges of a square washer to the baseplate?
Specifics:
1-1/2"Ø Anchor through 2-5/16"Ø holes in 1" baseplate
Square washer is 1/2"x3.5"x3.5" with a 1-9/16"Ø hole
While reviewing the drawing I haven't...
The geotech has provided an allowable bearing pressure of 2000psf. Because the provided pressure is allowable, I'd like to confirm that my loads (live, dead, hydrostatic, etc.) should not be factored?
Can wind turbines placed in a rural setting be considered risk category I per ASCE 7-10? The loss of a turbine does not pose a major threat to human life and they do not contain hazardous material in any substantial quantity.
Our contractor was performing a continuous pour for a wind turbine foundation. They interrupted the pour for 45min before continuing. Is this acceptable or does any ACI (or other provider) offer guidance on determining if this interruption is acceptable? Maybe these is some form of testing that...
