NCEES SE II

Hey, SE II takered,

First thing, just to inform that there is errata for NCEES SE II on there website incase you want are looking for it. Specifically, for Building problem 450 they have done a complete revision. It should be perfect in second time, however, I don't agree on solution for part d of the problem. I would appreciate if someone preparing for this exam or others can verify it.

(i)They have calculated column load E =26.7 k (and my calculation shows 13.35 k unless it is a tension only brace).

(ii)On load combination, they have used 1.2D+f1L+E. my opinion is they should replace f1L by 0.2S because it is a roof and where L belongs to floor live load not roof live load.

Thanks.

SE II prep,

Concrete Shear wall Design(non-seismic) Chapter 14 or chapter 11.10? My understanding is for shear wall we need to use chap 11.10

Regarding NCEES building problem 260 Errata -

1) they are using chapt 14.3.2 for minimum reinforcement for shear wall which is different from that of chap 11.10.- any comments ?

2) for load calculation the original solution uses 15% increase( based on shear =1.15V for first interior support) but the errata does not, I don't agree with the errata in this matter.

I would appreciate comments from SE prep guys.

thanks.

Regarding concrete shear walls, per ACI Section 14.2.3 and 14.3.1, they both refer to Chapter 11, Sections 11.10, 11.10.8 and 11.10.9.

Regarding Sample question 450:

(i) Unless otherwise indicated, I always assume x-bracing to be tension only.

(ii) I agree with you on the load combinations, use .2 for the snow. However they also included the roof top equipment load. Technically, the equipment is either dead load or roof live,Lr, which either way is not in the following LC: 1.2D + E + L +.2S

ARLORD said:

Regarding Sample question 450:
(i) Unless otherwise indicated, I always assume x-bracing to be tension only.

(ii) I agree with you on the load combinations, use .2 for the snow. However they also included the roof top equipment load. Technically, the equipment is either dead load or roof live,Lr, which either way is not in the following LC: 1.2D + E + L +.2S

Click to expand...

^^^I agree. Hopefully, they are just as lenient on the actual exam, since the practice material they publish is laced with mistakes

ARLORD said:

Regarding Sample question 450ii) I agree with you on the load combinations, use .2 for the snow. However they also included the roof top equipment load. Technically, the equipment is either dead load or roof live,Lr, which either way is not in the following LC: 1.2D + E + L +.2S

Click to expand...

To add to this... Could they be ignoring the snow load because it doesn't "exceed 30psf" as stated in ASCE 12.7.2.

I thought I saw a similar example where the question specified snow as 30psf, and it wasn't used in calculating W. However, I haven't been able to find that example. I'll have to dig a bit deeper I guess.

Casey said:

To add to this... Could they be ignoring the snow load because it doesn't "exceed 30psf" as stated in ASCE 12.7.2.
I thought I saw a similar example where the question specified snow as 30psf, and it wasn't used in calculating W. However, I haven't been able to find that example. I'll have to dig a bit deeper I guess.

Click to expand...

I don't think so. I don't think those two sections are realted.

Yes, that's true. ASCE 12.7.2 is about effective seismic weight not about load combination.

To add- according to IBC ASD Load combo you can ignore snow load if less than 30 psf. I don't see such provision on LRFD combo- dont know why.

Mcgill said:

Yes, that's true. ASCE 12.7.2 is about effective seismic weight not about load combination.To add- according to IBC ASD Load combo you can ignore snow load if less than 30 psf. I don't see such provision on LRFD combo- dont know why.

Click to expand...

Yes, got it. Never saw that before.

I have an idea.........Lets just use one code?

Mcgill said:

Yes, that's true. ASCE 12.7.2 is about effective seismic weight not about load combination.

Click to expand...

Sorry for the confusion. I had been wondering why they ignored the snow load for the calculation of W, so when I read your question that's all I was thinking about...

Mcgill said:

Hey, SE II takered,First thing, just to inform that there is errata for NCEES SE II on there website incase you want are looking for it. Specifically, for Building problem 450 they have done a complete revision. It should be perfect in second time, however, I don't agree on solution for part d of the problem. I would appreciate if someone preparing for this exam or others can verify it.

(i)They have calculated column load E =26.7 k (and my calculation shows 13.35 k unless it is a tension only brace).

(ii)On load combination, they have used 1.2D+f1L+E. my opinion is they should replace f1L by 0.2S because it is a roof and where L belongs to floor live load not roof live load.

Thanks.

Click to expand...

Some other inconsistencies with this particular sample question.

For 450 d.) instead of putting all the base shear into one foundation like they did with the braces in part c.) this time they divided the base shear over the two footings. This would lead one to believe that both braces are absorbing the lateral forces... If anyone knows why they might have divided the base shear over the two foundations instead of one, please explain; otherwise, I will assume it's a mistake in the errata.

Also in the same question when they determine the service loads on the footing they are not using proper allowable stress load combinations. Through their calculations they show that they use D + L( or Dequip) + E... Now regardless of whether or not the equipment is a live or dead load there is no such combination. Should they have not used D + 0.525E + 0.75L or D + 0.7E in accordance with IBC 1801.2 for the allowable bearing pressure? Can anyone confirm?

Thanks,

Casey