MSE Wall with traffic barrier and moment slab

[apriley]

I have seen previous posts about MSE walls with barriers, but I still need clarification.

Currently, Caltrans requires the use of BDS LFD for MSE wall design in lieu of AASHTO LRFD. Caltrans requires designing the moment slab and top row of MSE reinforcement for traffic impact. However, it is unclear what this impact force should be. The 54 kip load seems way too high, but I can't find anything about the 10 kip load from AASHTO in Caltrans BDS. All I can find is the 1.9 k/ft load for the top reinforcement (BDS 5.9.3.8.2), which still seems too high. I checked the standard XS sheet barrier slab overturning with the 1.9 k/ft load, and it doesn't work.

If anyone has an idea about what loads to use for 1) the moment slab, 2) pull-out, or 3) reinforcement tension, and where these are specified, I would appreciate it.

Thanks!

 

[jdonville]

apriley,

Doesn't Caltrans have a standard dwg/spec for the moment slab?! Perhaps you could ask a MSE wall supplier for a Caltrans detail.

Sorry, I wasn't more help.

Jeff

 

[apriley]

Jeff,

Yes, they do - but a check of their MSE charts for the soil reinforcement yielded less than desirable results (ie, it didn't work). So, I began to check into other aspects of the design, and couldn't find any loads for traffic impact other than the 54 kips over 10 feet, which is WAY too high for the standard. Even with 2 k/ft, the barrier slab doesn't work.

I'm going with the standard design, but I don't know what criteria they design for. Since I'm stamping the drawing, I wanted to make sure it worked.

Thanks!
AP