WATER-STOP METHOD FOR COFFERDAM USED IN BRIDGE PIER MAINTENANCE AND STRENGTHENING WORKS

摘要

To provide a water-stop method for a cofferdam structure used in bridge pier maintenance and strengthening works, in which water stop woks for the cofferdam structure can be easily carried out above water without requiring underwater works by divers.SOLUTION: A cylindrical cofferdam structure 3 is built surrounding the outer periphery of a bridge pier 1 at an unsubmerged part in the upper area of the bridge pier 1. The cofferdam structure 3 is lowered into water under the bridge for the bottom part of the cofferdam structure 3 to settle on a bed protection 2 at the bottom part of the bridge pier 1. An weight-attached water-stop sheet 16 is deployed from a water-stop work platform 15 arranged at an unsubmerged part of the cofferdam structure 3 onto the aforesaid bed protection 2 underwater to stop water by blocking the gap between the bottom of the cofferdam structure 3 and the top surface of the bed protection 2 with the weight-attached water-stop sheet 16 on the bed protection 2 being pushed by the water flow pressure.SELECTED DRAWING: Figure 11