personally it is the bored piles with cappingbeam and lagging wall. G
*ds4R?!
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. B>sCP"/uV
from the photo it can be seen that the site soil is not so bad. ob)Q,;8R
measures may be : soil nailing between the piles to increase the wholly stability of the wall; xC[~Fyhp
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; DCt\E/
meanwhile, monitoring should be carried out very carefully.