personally it is the bored piles with cappingbeam and lagging wall. |1/UC"f
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. ;%`oS.69
from the photo it can be seen that the site soil is not so bad. ,u@V i0
measures may be : soil nailing between the piles to increase the wholly stability of the wall; d #vo)>
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; ]Dd}^ khv
meanwhile, monitoring should be carried out very carefully.
