Horizontal ties at Change in retaining wall thickness 1

[MileyDiley]

http://ladbs.org/LADBSWeb/LADBS_Forms/PlanCheck/PC-GRAD.Corr11-GradingPlanCheck.pdf

The link above is to Los Angeles City's standard grading plan check list.

Item G. 2 (on page 5 of 6) states "Provide retaining wall details on plans, show: surface drains, subsurface drains, slope of backfill, tie at change in wall thickness and reinforcement."

What is meant by "tie at change in wall thickness and reinforcement"?

Please see attached sketch. The ties drawn in that are what the plan checker is requesting - I have never seen these and do not know what purpose they could serve. Anyone have any idea?

 

[msquared48]

Again, I agree with the plan checker as the horizontal bars will be resisting the breakout force from the stem wall steel.

Mike McCann
MMC Engineering

 

[MileyDiley]

I believe this was posted earlier but how is the top of the 12" section a problem but the bottom of the 8" section fine?

 

[JLNJ]

If you look at the new masonry code you will find that they have provisions for the confining properties of longitudinal bars. If there is a serious concern over the CMU splitting through it's width and the bars losing their bond, you might look at the provisions for sizing and locating those longitudinal bars.

I don't have the code in front of me, but I think using the longitudinal bars for confinement can cut your splice/embedment length by up to half. It also changes the nature of the failure, making it less sudden and brittle. All music to the code official's ears.

Is the upper bar offset on purpose or does it just look that way in the sketch? If it's too close to the face shell you might not be able to develop the bar properly. Maybe the bar's location and propensity to be misaligned in the field is a concern to the plan reviewer.

 

[MileyDiley]

I believe the 8" stem needed offset bars for moment capacity but yeah my mspaint sketch is probably exaggerated. Can you do me a favor and give me a reference for that (even though topic is now on tying the horizontal bars)? I'd appreciate it.