ABSTRACT
A compaction grouting method-based construction technology of retaining structures for deep foundation pits with H-shaped composite steel anchor piles-precast slab walls was revealed in this study. The construction process is as follows: a. Surveying, setting out, and pile positioning; b. Pile hanging in place and calibration; c. H-shaped steel pile driving; d. Excavation by layers and sections, and treatment of the pile body; e. Anchor rod driving from top to bottom in a way of “layer by layer, segment by segment, and rod by rod”; f. Hoisting of the precast slab wall in place; g. Insertion and binding of reinforcing bars firmly with the protruding reinforcing bars of the precast slab wall; h. “Layered and segmented” high-pressure grouting construction; j. Joint micro-expansion concrete pouring; k. Construction Step d to Step h are repeated; m. Reinforcing bar binding with the waist beam, formwork support, and concrete pouring; n. Acceptance inspection. In the technical scheme, an integral retaining structure for the foundation pit was formed using H-shaped steel piles, anchor rods and precast slab walls through a reasonable process. Then, the prefabricated construction of the retaining structure system for the foundation pit was implemented based on the principle of “excavation by layers and sections, anchoring layer by layer, section by section, and rod by rod, and grouting immediately after site hoisting”, which was safe and reliable and could effectively save the construction period, accompanied by the dual functions of soil retaining and water stopping.
