Pit-retaining Structure Construction Technique of H-shaped Steel Anchor Composite Pile- Prefabricated Wallboard Adopting Compaction Grouting Method of a High-rise Building in Guangzhou

Abstract

Taking the deep excavation engineering of a tall building in Guangzhou as an example, this paper introduces the pit-retaining structure construction technique of H-shaped steel anchor composite pile- prefabricated wallboard adopting compaction grouting method. The main construction process of this technique includes: (1) surveying setting-out to fix piles’ locations, (2) hoisting piles into place and adjustment, (3) H-shaped steel piles driving, (4) layered and segmented excavation and pile body treatment, (5) layered and segmented drilling anchor stocks one by one from top to bottom, (6) hoisting prefabricated wallboard in position, (7) inserting reinforcement and binding firmly with protruding bar of precast wallboard, (8) layered and segmented high pressure grouting, (9) pouring expansive concrete at joints,(10) repeated step(4) to step (9), (11) steel bar binding of middle beams, framework supporting and concrete grouting, (12) acceptance check. This method utilizes the integral foundation pit enclosure structure formed by the H-shaped steel pile, anchor rod and precast wallboard and the construction follows the principle of layered and segmented excavation, setting anchors step by step and grouting immediately after hoisting, which realize the assembly construction of the foundation pit enclosure structure and can effectively saving time, retain soil and seal water.