Design practice of local permanent excavation support under complex conditions

There are few excavation supporting projects in which the distance between basement exterior wall and column foundation is very close (about 0.66 m) and local permanent excavation support is included. The design difficulty is how to reasonably select the retaining structures and the bracing system. According to the design practice, the measures of square supporting piles and the anchors installed at supporting piles not to be set at middle beam for saving space are adopted for the retaining structures. And the measures of pressure dispersive anchors and anchor heads sealed by concrete cover where stirrup is installed in them and cementations capillary crystalline waterproofing coating materials are coated on their surfaces are adopted for the bracing system. The horizontal displacement and settlement of the excavation provided by the third party are relatively small, and it means that the design for the excavation is reasonable.