Recent studies suggest that battered piles do not perform well in liquefiable soils during a seismic event, and that piers and wharves supported by battered piles have historically not done so well in past earthquakes because they attract significant loads and typically fail the deck, pile or...
Have a contractor that would like to use API 5L X-60 (60 ksi) steel spiral welded pipe in lieu of A252 Gr. 3 spiral welded pipe for marine structural piles.
Anyone ever use API 5L pipe for structural piles? Other than the higher yield strength, I don't see much difference. API 5L is typically...
Hi All - hypothetical question:
Let's say we have a pipeline that carries a pressurized petroleum gas product for a distance near the shoreline, and the area is subject to liquefaction and lateral spreading.
Let's also say the pipeline is only full of product 5% to 10% of the time, empty the...
We're designing some pretty substantial conveyor galleries (25' wide x 100' long intermediate span) for an industrial project, in which the galleries are supported by bents every 100' and anchored for longitudinal seismic load about every 600' at a transfer tower (pinned at one tower, allowed to...
I don't know what others have experienced lately, but it seems like a lot of fresh graduates looking for work just don't want to put in the effort to set themselves apart from their peers. In the past couple weeks we've had a few engineering graduates stop by our office to inquire about open...
Hey all - I've got a question for those of you having experience with MOTEMS (Seismic design provisions for marine oil terminals in California).
Subsection 3104F.2.2 states that NDS allowable values for timber piles may be factored up by 2.8 to obtain ultimate values for seismic analysis...
http://www.dailyastorian.com/main.asp?FromHome=1&TypeID=1&ArticleID=65434&SectionID=2&SubSectionID=398
Not much detail in the news article, but at least there were no reported injuries. It's hard to tell from the picture but it appears the lower deck was timber construction.
This hotel is...
I recently came across the following in the 2005 ACI code:
21.2.5 - Reinforcement in members resisting earthquake-induced forces
Reinforcement resisting earthquake-induced flexural and axial forces in frame members and in structural wall boundary elements shall comply with ASTM A706. ASTM...
Hi all, I've recently come across something in ASCE 7-05 that concerns me with regard to non-building structures. Specifically, I'm having trouble with the following section:
15.7.10.4 Transfer of Lateral forces into support tower.
d. The connection of the post or leg with the foundation...
We are trying to determine whether or not it is possible to reinforce a W24x250 beam for shear near a support. Since the shear is only in one small portion of the beam, it seems uneconomical to increase the size of the already enormous beam when it is just one small portion that needs more...
We are doing a candian project, and the Canadian building code uses LRFD for everything, including factored bearing pressures. Anyway, we have been given an allowable factored bearing pressure of 2100psf for static loading, and only 1500psf under seismic loading conditions.
Typically, I've...
We had an online demonstration of RAM Connection last week and it looks like it could save us a lot of time. Currently we model our structures (mostly industrial steel structures) in RISA-3D and design connections by hand based on the highest loaded members. Some of the other engineers in our...
We are doing some preliminary design work for a Canadian project, and have limited experience with the BC building code. It appears that the all of the load combinations are limit state combinations (LRFD) - there are no service load combinations. When designing foundations for overturning /...
I attended an SEA seminar on seismic design using the 2006 IBC / ASCE 7-05 yesterday, and we were told that the first printing of the AISC 13th edition was full of errors. We were also told that if we send the first printing back to AISC we will be sent a copy of the second printing. I...
When designing anchor bolts for tanks and silos on braced legs, ASCE 7-05 states that the element design force is to be multiplied by omega (ASCE 7-05, 15.7.3 (a)) for anchorage. Thus, in addition to using factored loads for concrete design, and a .75 reduction on your allowables for anchorage...
So we just received the latest version of RISA 3D, v7.0 which now includes code checking from the AISC 13th. I thought I would do some code check comparing and noticed a pretty substantial difference between the LRFD 3rd edition and AISC 13th (LRFD) code check when looking at WT sections in...
It has come to our attention that the 2006 IBC now requires that you use only 2/3 of your dead load when calculating your overturning using ASD load combinations. Section 1605.3.2 states that "for load combinations that include the counteracting effects of dead and wind loads, only two thirds...
Greetings, my question is in regards to column base plates on grout leveling pads. We do a lot of industrial structures and have always used grout leveling pads underneath column base plates, typically 1-2" thick, on top of the concrete foundation (4000 psi typ.) I just noticed that when doing...
I am having trouble determining the best way to distribute an HS-20 surcharge on a wall. The structure I'm designing is a square underground pit with a grate on top, which HS-20 trucks will drive over to dump their load into. I tried distributing the load on the wall by converting the two 16k...
Hi all, just wondering if anyone could give me some assistance with floating viewports. I have a map which is in a viewport in paperspace. What I want to do is a blowup of a certain area by using a small floating viewport, and have it essentially inside the area occupied by the larger...
