My only problem with this question was the LRFD vs ASD. I automatically go for LRFD. Other than that I don’t really rely on that reference for any structural questions. It has almost nothing in it. Anyway, thanks for the question!

I think the formula comes from ACI- SP-4 Table 7.1 p 7-5 ; but honestly can just use the 3 span formula with load across only 2 of the spans: Continous Beam - Three Equal Spans - One End Span Unloaded (this is in the civil reference manual and aisc (diagram 37)). It is so similar to the real 2 span one doesn't matter on test . 3 span = 1.20wL while 2 span = 1.25wl . The correct way to do it though using the AISC: TABLE 3-22C (CONTINUOUS BEAMS MOMENTS AND SHEAR COEFFICIENTS): You will see a equal span equally loaded uniform load table. You will notice a "number" "arrow up" "number" divided by a "number" in the shear visual part under the reactions. These are the shears at the reaction points (they can be different positive and negative directions). To get total reaction at that point you should be adding these shear numbers up then dividing by the number under it then multiplying vs wL. L should not be the total length of continuous beam, only the span. For example (using ^ as up arrow): 4 span beam has 17^15 /(28) from the table. Negative shear = 17/28 * w * L (span only) which matches the diagrams in table 3-23 btw. The positive shear at that point is also 15/28 * w * L. To get the reaction it is ((17+15) / 28) * w * L (span only). For example in the video: It is "5" arrow up "5" divided by 8 in AISC TABLE 3-22C. ((5+5)/8) * w * L = correct answer. It just so happened the shears at the mid point are equivalent so multiplying by 2 for total length it just worked out, but in other situations it will get wrong answer.

I spoke with NCEES in my state and they said depending on your depth is what you will be given for references. Structural and Construction. If you are Water, Geotechnical, or Transportation you will NOT have access to these resources and only the Design Standards provided by NCEES for that specific depth. I would email or chat with your state board to verify this as well just to get full clarification.

We could still use the PE reference manual by using supersposition, since it is symmetric. Just assume another udl on the right span

Very helpful. I will say those continuous span tables like the tables from the steel manual are also in the PE reference manual.

You can find Rb=1.25wl in ACI SP-4 Table 7.1

Excellent, I feel this way with geotech that some statistical factors are referenced somewhere else and you have to know them by memory or know how to get them somehow

Thank you for sharing good explanation! can you share some examples for Geotechnical depth foundation design?

AISC is provided on the exam so all of the beam equations are there...

Result is correct, but I believe L=5, then it has to be multiplied by 2. Refer to 39 on Table 3-23 on AISC 15th edition (RB=1.1wl= 0.500wl+0.600wl). Hope someone can confirm. Amazing content btw!

Thanks so much for pointing it out. I do not know really why they this kind of Manuel . They have elaborated slot on water section and geotechnical that what required in addition they have taken out the import part of construction and structures . What is your opinion?

I assume that the PE reference manual thought you would use superposition for the load case where one span has weight and the other doesn't. By using superposition you would get an R2 of 5/4*w*L where w is as calculated and L is 5 ft giving the same answer.

started seeing discrepancies in my old paper/pen notes for water and the ncees hb 1.1. there are items which are missing in ncees hb 1.1. i think that this is fine AS LONG AS you make the hb 1.1 your bible and know what IS in it and what is NOT. study it assiduously. you cannot be allowed to become surprised, to be knocked off your feet during a time which is naturally already stressful. make it your best friend by practicing w it constantly. good luck!

Thanks. However, I don't see any equation for continuous beam - Two equal spans - distributed load in AISC. The 5wl/8 is for when the load is on only one span!

Was their intent with not including that diagram to see if you know how to use superposition?

I'm not finding the diagram for 2 span with a uniform load all the way across in the steel manual either.

I'm taking the computer based exam in october. a little worried about everything being computer based. Mainly worried about not being able to tab anything. Any tips on how to overcome this? Or should I plan on just remembering where to look and searching certain keywords?

You need to disturb the loads triangle and trapezoidal

Where do I find the LRFD load cases? I usually use AASHTO LRFD Table 3.4.1-1

Hi Rich! Thanks for great content. Are you familiar with sfrc desings? If so, it would be good subject for a video. Ps. Hieno nimi ja logo! Greetings from Finland.

Damn, I thought the answer was D

Could have used the virtual work method to solve for the unknown reaction, in the lieu of having to search through the steel manual. good content however!

Thank you Rich

Do you have the steel maul available to you during the computer-based PE exam?

You are doing wrong !!!