[waytootall]

Looks like they use the timber lagging as permanent shoring. Usually you would use secant or sheet piling for permanent retaining walls. But with soldier piles you could use precast concrete lagging or at least treated timber lagging for permanent applications. This looks untreated in which case it will deteriorate and will eventually load the ICF wall, which looks unreinforced vertically or at least too lightly reinforced to support lateral earth loads.