Construction scheme of three pipe high-pressure jet grouting pile cut-off wall

Content introduction 1.1.3.1 Construction process of three pipe high pressure jet grouting 1) Preparatory work: after "three connections and one leveling", two cement platforms and grouting platforms are arranged at one side of the construction axis of the three pipe high pressure jet grouting cut-off wall of the dam, working faces with a width of not less than 8.0m are arranged along the axis of the cut-off wall, and the high pressure jet grouting hole positions are measured on the axis of the cut-off wall according to the "Plan Layout of Hole Locations of High Pressure Jet Grouting Cutoff Wall", And make marks. After the hole location is determined, the drilling rig and high-pressure spray jumbo can be put in place and the equipment can be installed and debugged to prepare for the formal construction. 2) Slurry preparation: as the stratum is mainly dam filling soil, slurry wall protection will be used for hole making. High quality clay will be used for slurry preparation. The specific gravity of slurry is controlled at 1.08~1.2, the viscosity is 17~20s, the colloid rate is>90%, and the sand content is<4%. 3) Drilling: PH-5B deep mixing pile machine is used for drilling, with a hole diameter of φ 150mm. Mud retaining wall positive circulation drilling is used. The hole depth is controlled according to the design requirements. The construction is divided into two sequence holes. During the drilling process, attention should be paid to controlling the proportion of mud, avoiding hole collapse and drilling burying, and controlling the hole slope<1.0%. 4) High pressure jet grouting: according to the design requirements, a triple tube parallel jet pipe is used. The jet pipe is longer than the hole depth, and the one-time lifting and spraying are completed to ensure the continuity and integrity of the cut-off wall.