U-SHAPED STRUCTURAL UNDERPINNING TRANSFER SYSTEM FOR BRIDGE PILE FOUNDATION AND CONSTRUCTION METHOD THEREFOR

摘要

A U-shaped structural underpinning transfer system for a bridge pile foundation, comprising: cofferdams constructed on either side of an existing bridge; high-pressure jet grouting piles (6) constructed around existing pile foundations of the existing bridge and a riverbed between the cofferdams; a graded gravel mattress layer (15) constructed at the tops of the high-pressure jet grouting piles (6); a plain concrete bedding (7) provided on the graded gravel mattress layer (15); bearing platform embedded steel bars (9) constructed on the inner side surfaces of a bridge pile foundation bearing platform (3) of the existing bridge; bridge abutment embedded steel bars (10) constructed on the inner side surfaces of a bridge pile foundation bridge abutment (4) of the existing bridge; and a cast-in-situ U-shaped structural raft (8) constructed between the inner side of the bridge pile foundation bearing platform (3) of the existing bridge, the inner side of the bridge pile foundation bridge abutment (4) of the existing bridge, and the plain concrete bedding (7), a 4-cm gap (11) being formed between the top surface of the cast-in-situ U-shaped structural raft (8) and the bottom surface of a bridge deck (5) of the existing bridge. Also provided is a construction method for a U-shaped structural underpinning transfer system for a bridge pile foundation.