Most of us are familiar with the concept of designing a concrete beam for Vu @ d, that is for the shear at a distance 'd' from the face of the support. At this critical distance, the shear in a simple span beam is typically less than at the end or face of support (FOS) which results in a...
The NYC Building code gives presumptive load bearing values for soil types that are considerably higher than the presumptive bearing values of the IRC/IBC codes. The Data Book for Civil Engineers by Elwyn E. Seele cited these values from the NYC code back in the 1940s-1950s in a manner that...
NDS Equation C12.2.5-2 for fastener head pull-through uses "Fastener Head Perimeter", P-sub-H. What is "fastener head perimeter" and how is this obtained for common hex head bolt sizes? And, how does using a washer come into play when used with fasteners with other than round heads such as hex...
Let's say a 3/4" hole is formed in precast concrete slab so that a 1/2" or 5/8" bolt can later be inserted through the hole to be an anchor. Would this anchor be considered cast-in or post-installed for the purpose of determining factors per ACI 318-19 Ch. 17?
An argument for considering the...
Can Chapter 17 be applied for anchorage to masonry such as solid grouted CMU? The provisions of ACI 530 to calculate axial and shear strength for anchor bolts embedded in grout seem rather basic and are only a function of f'm and assumed breakout cone, so it would seem that ACI 318 Ch. 17 could...
Let's say you have a thin concrete slab, 3-4" thick. A thru-bolt will be used to pass through the slab to carry a load with tension and shear. The bolt will bear on a 3" square steel plate and the center of the bolt hole will be about 2.5" from one edge of the slab. Do you look at the...
When using the Vesic Method for calculating bearing pressure, is it more appropriate to use effective stress or total stress? I have some lab measured data for a soil where the lab reported both phi and cohesion for the soil samples, but I get varying results depending on which I use. The total...
How does eqn 17.6.2.6.1b work if (ca,min / cac) is NOT greater than or equal to (1.5 hef / cac)?
For example, if
ca,min = 3"
cac = 6.375"
hef = 4.24"
then (ca,min / cac) = 0.47 and (1.5 hef / cac) = 0.99
0.47 is NOT greater than or equal to 0.99
Is the Breakout Splitting Factor (Psi-sub...
What is the current code requirement for any reduction in foundation self-weight (D) when resisting wind uplift (W)?
2021 IBC contains the following verbiage:
"For load combinations that include the counteracting effects of dead and wind loads, only two-thirds of the minimum dead load likely...
This question is specific to paragraph 4, subpart F on page 4 of 9 of the administrative complaint below where the prosecuted engineer was charged with failing to "reference any generally accepted engineering standards". The way I interpret this charge, simply referencing the building code was...
The standard definition for concrete cover seems to be "the least distance between the surface of embedded reinforcement and the surface of the concrete" (ACI ITG-7-2)
In cross section, this is typically specified from the edge of the bars to the face of the concrete.
Is anyone aware of any...
I find R301.2.1 in IRC to be very unclear as to when wind design is and is not required. The first sentence reads "Buildings and portions thereof shall be constructed in accordance with the wind provisions of this code using the ultimate wind speed in Table R301.2 as determined from Figure...
This is more of a theoretical question than a practical one, but in principle, what is the difference between a PT beam and a column with bending? Say you had a simple rectangular concrete beam with straight (no drape) unbonded PT at a given eccentricity and an applied uniform load. Instead of...
Is there an acceptable way to account for or provide supplemental reinforcing for a concrete anchor? As in the attached sketch, a rebar is placed perpendicular to the anchor so that it runs continuously through the failure cone. Not sure if shear-friction would apply since the bar wouldn't be...
ACI 318-19 Section 9.6.3 gives requirements for minimum shear reinforcing, Av,min. It says "Av,min shall be provided in all regions where..."
However, in Table 22.5.5.1 for Vc, equation (c) is provided for cases when Av < Av,min
My understating of equation (c) based on a seminar I sat in is...
The IRC, as we are all familiar, provides prescriptive design standards meant to cover common construction of “one and two family dwellings and townhouses up to three stories.” Examples of this prescriptive design include connections such as from wall to foundation, headers over openings, etc...
Note 3 in Table 12E of NDS 2018 assumes dowel bearing strength, Fe, of 7,500 psi for concrete with f’c = 2,500 psi.
How do you get 7,500 psi bearing strength for 2,500 psi concrete and be in accordance with ACI 318-19 22.8.3?
Considering the attached sketch, how would you apply the soil forces to this wall? In other words, how does the soil on the right respond to the soil on the left...how much can the resultant of the soil on the left be reduced by the soil on the...
Especially in residential construction, it can be common in practice to use construction adhesive in addition to mechanical fasteners to make connections. Examples of this would include sill plates on foundation walls, wood sheathing to support members, sistering joists, etc. As a structural...
