Seismic Retaining Wall Reinforcement Design

[TobyT]

Designing the reinforcement for a retaining wall attached to a bridge abutment. For the stem, I've calculated the active lateral earth pressure and the seismic lateral earth pressure (using monobe-okobe). In addition, if I consider the mass x accel of soil on heel and abutment stem DL, the moment for the reinforcment design become huge. I haven't been able to find any help in AASHTO.

I'm inclined to neglect the inertia of the soil and wall, and just use standard governing load combinations considering the active and seismic earth pressures for this reinforcement design. These factors have already been considered in the stability analysis.

Any suggestions and/or code references would be greatly appreciated!

 

[crossframe]

My impression is that the Mononobe-Okabe IS the seismic force and the (Soil Mass x A) check is not required. Besides, the wall will usually move with the soil.

Note too, that the Mononobe-Okabe equation already includes the active earth pressure, so an E + EQ load combination can "double count" active earth pressure unless you're paying attention to it.

 

[civilperson]

The DL on the top of the wall does contribute to the moment. The soil behind the wall is included in Monobe-Okabe equation when applied 0.6h up the wall from the heel/base.