Hiner multiple choice problems on Chapter 9

[Bruin]

I'm having a hard time understanding quite a few problems in chapter 9. I hope someone can help me.

9.8. why was drag force calculated from the south end? I am still having a hard time drawing drag force diagram. Can someone show me what the diagram for the two North-South wall look like (eventhough it's not part of the question)?

9.11. Which panel grade is the solution from? Why?

9.12. The load is parallel to continuous panel joints. Why Case 3? Why not Case 4? where in table 2306.3.1 did the answer come from?

Thank you very much in advance.

 

[sac_engineer]

I'm having a hard time understanding quite a few problems in chapter 9. I hope someone can help me.
9.8. why was drag force calculated from the south end? I am still having a hard time drawing drag force diagram. Can someone show me what the diagram for the two North-South wall look like (eventhough it's not part of the question)?

9.11. Which panel grade is the solution from? Why?

9.12. The load is parallel to continuous panel joints. Why Case 3? Why not Case 4? where in table 2306.3.1 did the answer come from?

Thank you very much in advance.

9.8: The drag force is greatest where the collector member (i.e. opening in wall) is the longest because the longer the opening , the more drag force the shear wall will undergo to resist the diaphragm shear.

9.11 this is a nailing substitution problem and ensure that the allowable shear isn't less than the previous design (340 plf)

9.12 Case 3 is better than Case 4, but the point is that the load is parallel to the panel joints. You need to find a nail type and spacing that will satisfy the 275 plf design. For a 2" framing member, none of the unblocked diaphragms will be acceptable, therefore the next step from 275 plf is 320 plf (10d @ 6" oc blocked)

 

[Bruin]

Thank you for your help. I think it sorta makes sense now. I missed the title of the table that differentiate between diaphragm and shear walls.... But I got it now... Thanks so much.