Working Mechanism of High-Pressure Rotary Jet Drilling Rigs in Foundation Grouting

Working Mechanism of High-Pressure Rotary Jet Drilling Rigs in Foundation Grouting

The high-pressure rotary jet drilling rig realizes foundation reinforcement through the integrated working mechanism of high-pressure jet cutting, stratum disturbance, grout-soil mixing, and static solidification, which is the core technical principle of foundation grouting and pile forming. The whole working process is divided into three stages: hole forming, jet grouting, and solidification forming. 

In the hole forming stage, the drilling rig drives the drill rod and drill bit to drill to the designed foundation depth through rotary feeding, completing the pre-buried hole channel for jet grouting and ensuring accurate hole position and verticality. In the core jet grouting stage, the high-pressure system pressurizes water, cement slurry, and compressed air to standard working parameters, and the multi-channel nozzle at the bottom of the drill rod ejects high-speed jet fluid. The high-pressure jet produces strong impact cutting force, which continuously cuts and disturbs the surrounding soil layer, breaking the original soil structure and stripping soil particles. 

At the same time, with the uniform rotation and slow lifting of the drill rod, the jet fluid drives cement slurry to fully mix with disturbed soil particles, forming a uniform grout-soil mixture in the rotary lifting range. In the solidification forming stage, after the drill rod is completely lifted, the grout-soil mixture fills the drilling hole and surrounding disturbed areas, and through physical precipitation and chemical hydration reaction of cement, the mixture gradually solidifies to form a continuous, high-strength, impermeable reinforced pile body. Different from traditional grouting, the rotary jet mechanism relies on high-pressure jet power to actively transform the stratum structure, rather than simply filling pores. Single-pipe, double-pipe, and triple-pipe processes adjust jet medium and pressure matching to control pile diameter and reinforcement depth. This working mechanism effectively improves foundation bearing capacity, reduces soil permeability, and realizes integrated foundation reinforcement and anti-seepage treatment.