Design of Walls - Simplified Method - Restraint of Vertical Reinforcement - AS3600-2018 1

[Drapes]

I refer to the new concrete code AS3600-2018 under "Section 11 - Design of Walls, clause 11.7.4 - Restraint of Vertical Reinforcement" - see attached excerpt.

With reference to the last statement, does this only apply for walls that are designed as columns, or for walls in general whether they are designed as columns or designed using the simplified method for walls?

The reason I ask is because the preceding statement under this clause relates to walls designed as columns, so unsure if this last statement is simply a follow up requirement, or if it should be read in isolation.

 

[Drapes]

rapt,

Are you saying that we can only design shear walls as limited ductile or moderately ductile (mu>1), if we first verify that the wall will crack under earthquake load combinations (say with G+0.3Q+EQx+0.3EQy) based on the non-ductile parameters which uses the "full" earthquake load? What if you have a core, which will be subject to cracking on the lower levels, but not on the upper levels - can you consider the whole core as limited or moderately ductile at the outset, and design accordingly, even if the core will remain uncracked in some areas?

 

[rapt]

Drapes,

This is all getting to complicated to answer here.

I responded to the last sentence in QSIN's last post where the question was regarding ignoring ties in a wall that does not crack under a design load determined from mu = 2 and Sp = .77. Nothing else.

There are currently 3 places in the chapter 11 of 2018 code that specifically require that mu = 1 and Sp = .77 or 1 be used in specific checks for detailing of walls. I have also commented that there should be one in the column confinement rules in chapter 11 and possibly something should be said in chapter 10 on column confinement for earthquakes. There is also one in Chapter 14 on force analysis for diaphragms.

The Commentary for the new code is currently being written and will hopefully explain all of it and will have references. Otherwise get a copy of Priestlys last book on it.