In our region (Puget Sound WA), it seems like Geotechs keep increasing their seismic surcharge recommendations.
In the days prior to it being a code requirment, the few Geotechs ahead of the curve were commonly recommending about 8H (in psf)
Once it became codified, the design...
Appreciate the feedback. Thanks for all the resources.
As far as the detailing that falls into the "not how I would have done it" camp...
Do we think insisting on detailing that make sense to non-PEMB structural designers would make suppliers non-competitive?
Looking for guidance regarding structural design for pre-fabricated metal buildings.
We're talking the classic structural steel moment frame "bents" with light gauge purlins & girts with metal deck/siding.
Seems like the standard in the US is for these structures to be designed by the supplier...
We've recently been asked to provide structural calcs for precast concrete stair treads.
Most suppliers are providing 2.5" thick treads x up to 4 feet spans and 3" thick for spans above that.
ACI 318 Cover Requirements:
A. < #5 bar in precast elements exposed to earth or weather = 1.25 inch.
B...
In our area (Western WA), it's very common to work without a Geotechnical report for residential construction.
The acceptable standard by most jurisdicttions is to use 1,500 psf for allowable bearing pressures.
I presume this is intended to cover a "worst possible case" based on the lowest...
That seems enormous to be a precast element (9,800 ft3 of storage). Based on preliminary designs, the box would weigh approx 400 kips. Maybe multiple precast boxes, but then they would all have to be tied together etc. Prob a lot easier to dig one giant hole and combine all the storage into...
The reviewer is also asking for Fire Truck outrigger loads.
Having said that, we're only spanning 14 feet, which is well within the capacity of their standard planks (even for all the different vehicle loads). The one component that isn't understood at the moment is the soil cover depth of a...
Vault is a single cell that's approx 100ft x 14ft x 7 feet tall.
We'll have two load configurations.
1. Current Design = 15 offset from road with sloped (up to 8 feet) landscaped cover.
This will probably control for the design of the concrete wall portions of the vault.
2. Future Layout = The...
We've been asked to design a buried detention vault that is in a right of way along a major city street.
Because of this, the City is requiring that we conform to the relavent transportation codes.
1. AASHTO LFRD Bridge Design Specifications.
2. WSDOT Bridge Design Manual.
3. WSDOT Geotechnical...
We have some decent size openings that will need heavy reinforcing and likely pilasters for the jambs.
One more thing, we've got an in-house spreadsheet that does the iterative slender wall analysis and a generic software package that has a slender CMU wall option. In the software, there are...
Yes, Not going to be able to avoid 10-inch block and possibly even 12-inch.
I'm guessing the masonry subcontractor will prefer no bigger than #5 vertical bars which may result in a pretty tight spacing (trying to avoid getting clear down to 16" oc). If that's a little tight, how much is the...
We're working on an industrial project where the owner wants the exterior shell to be CMU.
It's quite tall in places + 29 feet and in a high seismic area (Sds = 0.816) so we're definitely needing to use the slender wall design procedure.
Several designs are possible involving multiple...
Well,
Stepped footings aren't an option because the pipes are in the same general location and direction that the stemwall or plinths would need to be. I would also agree that it's generally best to avoid mixing foundation systems (although sometimes they're needed for sites with existing fills...
Thanks everyone,
Another option we've come up with is to add some pin piles. After speaking with a pile contractor, we could probably make it work with (4) pin piles under each spread footing and potentially another couple under the stemwall footings in between each spread footing.
They said...
We're working on a site with a new 3-story building replacing a previous structure. Prior to the footing excavations they had a utility locating service come out and discovered 3 lines (4" + 4" + 3" water and storm lines) running directly under a highly loaded bearing line! The pipes are...
