Because of the high-speed jet stream is a high energy concentration and continuously acting on the soil three pipes Rotary Jetting Water Curtain, stress and erosion and other factors always occur at the same time effect of intensive stress in the region. So cement mixing Pile Cofferdam, with the impact of the jet cutting and destruction of soil and soil slurry mixing functions. Pressure circle spray reinforcement mechanism: the mechanism of high pressure jet grouting foundation reinforcement mainly in three areas: high pressure rotary jet cutting undermine the role of the soil body, the jet impact soil in pulses rotating water - resisting curtain, so that the soil structural damage voids ; mixing effect, drill in the rotation and promotion process, voids are formed in the back of the jet, at lower injection pressure, forcing soil particles to move in the opposite direction of the nozzle (ie little resistance direction), and the slurry was stirred After the formation of the chemical reaction when mixed consolidation thereof; compressive effect, high-pressure jet cutting broken soil in the process, there is a surplus in the broken belt edge pressure, which has a compressive effect on the soil.