POST GROUTING SYSTEM OF CAST-IN-PLACE CONCRETE PILES AND THE POST GROUTING METHOD FOR INCREASING END BEARING CAPACITY AT PILE BASE

摘要

PURPOSE: A post grouting apparatus and method for cast-in-place concrete piles are provided to prevent the supporting force reduction and settlement of the piles by increasing end bearing capacity at the pile base. CONSTITUTION: A post grouting apparatus for cast-in-place concrete piles comprises a reinforcement steel net(4), an injection pipe(6), an outflow pipe(8), a Manchette tube(10), a connection unit, a grout injector(14), and a packer(16). The reinforcement steel net is inserted a bore hole(2) which is drilled in order to install cast-in-place piles. The injection pipe is attached to the reinforcement steel net and vertically installed to put in a grout material. The outflow pipe is attached to the reinforcement steel net and vertically installed to confirm the outflow of the injected grout material. The Manchette tube includes an outlet for squirting the grout material to the adjacent ground. The connection unit interlinks the injection nozzle, the overflow pipe, and the Manchette tube. The grout injector is connected to the head of the injection pipe and injects the grout material at high pressure. The packer is formed on the ground side ends of the injection pipe and the overflow pipe and applies high pressure into the injection pipe and the outflow pipe.