Drilled shear pin caisson

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I am working on a residential custom home and at the backyard there is a new 6ft retaining wall supporting a descending slope. The soils report provides all the design values that I need, but to provide slope stability they are requiring that a row of drilled shear pin caissons with shear strength capacity of 370kips be installed along the wall length. I had anticipated using caissons and lagging as permanent shoring and the concrete retaining wall will span between the caissons, but I am unfamiliar with what a shear pin caisson is and how to design it.

My question is besides the active pressure from the wall what additional loading is this shear pin caisson designed for? I asked the soils engineer and he said he would send me some information on it, but based on his answer he didn't seem to know how the 370kips should be applied to the caisson. Should it be applied at the resisting surface below grade?

Any info would be greatly appreciated.

 

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Just a follow up on my Q, in case you are interested. I spoke with the engineering geologist and he said that the caissons should have 370kips of shear capacity, but not actually designed, as far as the embedment of the caisson, for this load.

It makes sense, since in order to fully stabilize the slope would require tie backs, which can't be used in this condition, or some other massive extremely expensive system.
I guess they want to make sure that the caissons are capable of resisting the 370 kips of shear load, but the soil below would fail before the caissons. At least that is my understanding.