Is there a minimum vehicle design speed where AASHTO requires the dynamic load allowance be considered, or are they silent to it and so conservatively it would need to apply at all design speeds? Application is design of access hatch for underground vault in sidewalk that can be driven onto at...
It appears there is an industry preference of "stretcher" block CMU over a standard ended unit in the field of the wall. Can someone provide insight into the advantages of using "stretcher" block. Also, Is it possible to fully grout walls constructed using "stretcher" block?
Thanks for the response;. On the topic of 0.7 I will note it is my belief you are using a relic of older code editions referencing allowable wind loads (ASCE 7-05). The 0.7 was an adjustment to take the 50 year MRI down to a 10 year MRI for deflection considerations. Current IBC which used...
In the context of:
exterior wood wall stud with typical window components
FBC 2023 code (IBC 2021 with amendments)
interior gypsum wall board
flexible exterior finishes
What is correct FBC interpretation/application for deflection ratio and wind load factor?:
0.42xW and L/120 (Table 1604.3...
IBC calls for (1) 16d face nail and (1) 16d toe nail for 2x lumber decking. NDS SPDWS call for (2) 16d nails at intermediate supports to substantiate a diaphragm for horizontally sheathed lumber decking. Does the toe nail qualify as one of the nails for the diaphragm?
ACI 360-10 provides recommendations for unreinforced slabs on grade contraction joint spacing of 24 to 36 times thickness of slab
ACI 360-10 8.3 speaks to 0.5% reinforcement to eliminate the need for contraction joints
ACI 360-10 8.1 notes benefits of reinforcement allow for "use of longer...
In evaluation of a masonry shearwall should one use the horizontal section properties (vertically spanning) or vertical section properties (horizontally spanning)?
Regarding Tilt-up concrete wall construction and in plane shear resistance at the wall to footing interface I note ACI 551_2R-15 comments:
"The coefficient of friction for factored sliding resistance between the panel bottom and the footing can usually be taken as 0.6. Supplemental positive...
I am trying to develop wave loads for a structure where I expect the wave(assumed to be depth limited) will over top the structure. Using the ASCE 7 equations and just neglecting the portion of the pressure diagram where it will be overtopped I am coming up with load much higher than...
Is progressive collapse still a consideration for one story structures. I am working with ASCE 7 and the UFC codes. Obviously from a gravity perspective if a column is knocked out that portion of the roof comes down. But how about lateral systems does progressive extend to redundant lateral...
I see aashto provides guidance on p-multipliers for a py lateral pile/drilled shaft analysis group effect. I am using LPile and have two questions regarding the application of this:
1. LPile allows for varying the p-multiplier based on depth below pile head; does anyone have guidance on how you...
When you add a soil key to increase sliding resistance my understanding is that you can consider soil on soil tan(phi) friction as opposed to soil on concrete tan(2/3*phi) since the failure plane will be through the soil. Can anyone provide a reference that supports this? Also under this...
Trying to decipher tie requirements for a gravity only column in a SDC D structure. It seems regardless of whether you evaluate the design displacement or not they send you to 18.7.6 which requires shear force calculated from Mpr? If so it seems the tie requirements are almost the same as it if...
In dealing with a coastal structure, at what proximity to the shoreline to you start considering it having atmospheric exposure?
How about if your on an island but a 1-2 miles or two from the shoreline?
At what point are you C1 or C2 concrete exposure?
At what point do you need increased...
My second example was bad; P big delta certainly exists there but would be underestimated with pin assumption.
EZBuilding - How about we talk about a pin pin gravity column subject to drift at top. I agree compression would go up due to p big delta because of angle but secondary moment effects...
Interested in other's thoughts on P big delta affect when designing with a pin base design assumption.
With a pin base idealization, p big delta doesn't theoretically exist, and drift of structure would just result in a shear thrust at the base, no?
But since pin idealizations usually always...
Do you think the top profile on the attached meets the intent of ASCE 7-16 §26.8.1.2? The bottom profile is my interpretation of the ASCE 7-16 commentary section, by this interpretation the site location in the top profile would need to be 280 ft x 2 + 280 ft = 840 ft and it is only 561 ft so it...
In looking at ACI 318-14 I see where Shear Caps are addressed in section 8.2.5 where it is required they extend a distance from the column face equal or greater than their depth below. I don't see where column capitals are addressed. I take the distinction between a shear cap vs. capital is one...
bookowski - I considered this as well, but wouldn't excessive cover on top lead to potential crack width control concerns in negative moment regions? I suppose this is one of my concerns with a fully adhered (composite) behavior...maybe less of an issue with a real roof covering but not sure...
