This is less a engineering question and more a product question. I have someone wanting to anchor to an existing 3" thick, light-weight slab in seismic design category D (cracked concrete). I can't find any anchor that is tested in anything less than 3.25" (1/4" Hilti KB-TZ2). LRFD shear load...
I thought it would be another year and a half before I had to worry about using the ASCE 7-22, but I just discovered that the new FL building code (8th Ed) coming effective in January has adopted the ASCE 7-22 (per chapter 35) in lieu of the ASCE 7-16 which should have been adopted since the 8th...
I'll admit that concrete knowledge is the weakest amongst building materials, so I only get involved in very simple concrete things. Well, I am being asked for a letter of approval for the concrete used in sonotube piers used for bearing and lateral resistance of a single-story modular building...
I've searched for my answer, but it seems past discussions never anchored down an opinion (pun intended).
I have clients always upset that I make them switch their hot-dipped galvanized, post-cast mechanical anchors for stainless steel when the anchor is located outdoors. I always reference the...
I was informed that the concrete pier was installed 2" off the mark. The steel structure is pre-fabricated and there is no way to move the steel. I was asked if they could cut the cast-in place anchors and drill new holes shifted 2" for post-installed anchors. I'm concerned because the new...
I'm probably one of the last converts from the old RISA. I have, until yesterday, ran version 17. I am now in version 21 and I like some of the features and some I don't. I like that I can manipulate multiple nodes by entering coordinates rather than having to "move" them. I like how fast it...
I am a structural engineer tasked with finding the maximum wire run length for a simple modular building. The panel has 120v receps with the branch load rating of 900 Watts. So, I'm working with 7.5 amps. I am allowed 2% voltage drop on the branch circuit (ASHRAE requirement I believe). Googling...
I've always used envelope because my projects are mostly small rectangular, modular buildings. I've been practicing for 15 years and I rarely use directional. However, today I have a job that, for simplicity, is 60'x60' with 9' walls and gable roof with a 4:12 pitch. Normally, it doesn't happen...
I am in the midst of moving and my 2014 AL design manual is in my shipping pod, so I don't have access to it. I am working from a previous calculation and I have my fillet weld calculation as shown below. Can anyone tell me:
[ol 1]
Why am I multiplying Ftuw by 0.85? I don't know if has something...
I'm going to ask a question that may make you wonder how I got my SE.
Is the centroid synonymous with the neutral axis, which is not (might not) be the same as the plastic neutral axis? Every time I hear neutral axis, I think plastic neutral axis. However, I am in the Aluminum Design Manual...
I'm looking for some thoughts. I have an elevated tank with granular fill supported on concentrically braced columns (R=3, Omega=2). I have run the load combinations without overstrength and there is no net uplift (actually minimum compressive force is ~230 kip [(0.9-0.2SDS)*D+E]) and worst-case...
ASCE 7-10, section 12.7 says to use 25% of the live load for live loads that are considered storage. My question is what happens to the load combinations (ASD for the sake of this conversation)? I have to have live load in order for 25% of that load to be considered seismic mass, so D+0.7E no...
Once again, I have a concrete question. I have a 71.6 kip LRFD load coming down an 8"x8" tube column. There is an existing 18' hexagon concrete pad (3' thick) on the site. The new construction hits the existing pad on the edge as shown below. The 8" tube is flush with the edge of the concrete...
I have a 5.5" wide by 5/8" thick TRANSVERSE plate welded to an HSS8x8x3/8, because I am creating a W-flange beam to HSS moment connection.
Per equation K4-4, my calculated effective weld is 3.42" even though there will be 11" of weld (5.5" across top and bottom of plate). Based on my load and...
Let's say I have 3" of 5000 psi concrete (3" topper of a 6" thick deck), such that le=da=3". I want to put plates on both sides and bolt through the concrete with 3/4" A36 rod to connect the plates. The closest edge distance is 20.5" (ca1). I am using ACI 318-14. Avco (17.5.2.1) is very large...
I recently had the privilege of doing a project for MD (2015 IBC). One of my deviations was that I must list both Vult and Vasd on the drawings. I did it to please the state, but I don't know why I had to do it. They referenced section 1609.3.1 as the requirement for listing both, but I still...
I am trying to calculate the brace force of the attached frame. I can do it easily in RISA, but I want to incorporate it into a MathCAD calculation because it will be easier and faster to produce a calculation set for future projects. I've been racking my brain to figure it out because I know...
I have a small canopy that I am designing (10x17) that will be located just outside of a strip-mall supermarket (high walls, deep roof (upper roof length = 115')). The canopy is tight against the building, so I have drift loads on the canopy. Because of the depth of the supermarket, I am getting...
I have a 4" thick, precast wall (~14' long). I want to use the sidewalls of the 10'x14' unit to span piers (0', 7', and 14'). The walls must support the roof distributed loads and the floor distributed loads (applied as point loads at welded connections between floor and walls). One of the 14'...
I have to check a canopy going to Chicago. It is less than 200' so the lateral MWFRS wind pressure from column A is 20 psf. It is an open structure, so the uplift is 100% of that value [20 psf]. It is basically just a parapet, so the lateral force is 200% of that value [40 psf]. This is MUCH...
