The heavy rainfall caused many foundation pit collapse and induced tilt and wall cracking of building around the pit. Partial collapse located below the building foundation, which induced foundation impending and indoor ground subsidence and some facilities damaged.
The porosity of the soil can be filled compacted by rock bolt reinforcement, which was eroded by the heavy rain. With the grouting reinforcement, the soil shear strength can be improved, the bearing capacity of the self drilling rock anchor increased, so as to improve the safety factor of the foundation pit. Simultaneously the waterproof curtain of the west and the south can be strengthen to reduce the influence of the settlement of the surrounding buildings.
Water accumulation in the foundation pit is equal to the back pressure stack, beneficial to the stability of the slope itself. If pumping before reinforcement, which is likely apply horizontal load to the existing foundation pit side wall and is adverse to safety of foundation pit. So it is to maintain a pit water level constant during grouting reinforcement, until to the new anchor constructed, the water level can be gradually reduced.
Soil around the foundation pit must be grouting reinforcement, while there are different grouting reinforcement scope restricted by the construction space.