personally it is the bored piles with cappingbeam and lagging wall. hV]]%zwR+
the main reason for this collapse may be the shortage of bending moment resistance of the wall. the surrounding building is the critical origin of the large lateral force. _B5vh(.
from the photo it can be seen that the site soil is not so bad. 8%D 2G i
measures may be : soil nailing between the piles to increase the wholly stability of the wall; iSg^np
increase the embedment (if the collapse came from overturning of the wall); prop up the wall with berms or inclined wall; or tie back from the back of the wall; YE5B^sQ1
meanwhile, monitoring should be carried out very carefully.