Retaining wall resting on a sloping ground

[SamWagga]

Hello Everyone,
My first thread in this forum.

I am designing a reinforced block retaining wall (60 m long and 2 m high). The wall will rest on an inclined frictional plane along its length. The slope is 2 degrees so the difference will be almost 35mm every meter long or 2.1m for the hole length.



Is this concept accepted by geotechnical engineers? If so, what would be the maximum allowable slope?

 

[EireChch]

Embed the footing and then run it horizontally, then at some point you will need to step the wall as it tries to run out of ground. If you embed 600mm and allow a minimum of 300mm embedment, you will need at step every 8.5m (300/35).

Dont rely on any passive resistance.

 

[BridgeSmith]

This is a block-faced mechanically stabilized earth (MSE) wall, correct? A 2% slope along the wall is nothing to be concerned about from a stability standpoint; the internal friction will be plenty high enough.

As a practical matter, balancing the extra labor for more steps in the base under the wall against the extra excavation and material to start with deeper embedment, to find the least cost option is a bit of a guessing game. The blocks we use are 8" high, so we always detail the steps in multiples of 8". For something with your slope, we would typically step it in 24" increments.

We typically have a minimum embedment below the local frost penetration depth, if not for the wall itself, at least for the bottom of the granular base material (crushed base) under the blocks. If you don't have to contend with freezing ground, the 300mm suggested by EireChch seems reasonable, if there aren't any erosion concerns in front of the wall.

 

[SamWagga]

Thanks guys,

I can not run the footing horizontally as the brick units are high (about 800mm high) and I need to align them to run the horizontal reinforcement. That's why I am trying to explore options like ruining the footing on a slope.

I guess such wall, adding articulated joints and shear keys to the footing every 6 meters, and having proper reinforcement, is structurally possible, but I am not sure if running a wall along a sloping ground is geotechnically adequate or if this big difference in height (due to the slope) is considered as differential settlement.