Application Study Of High Pressure Jet Grouting Under Conditions Of Gravel Soil

High pressure jet grouting was founded in Japan. Based on the traditional grouting method, with the application in the hydraulic mining, high-pressure water jet technology developed. At that time, the construction of this new method of reinforcement is mainly used to deal with soft soil. At present, the technology out from the construction site constraints, with many advantages ,such as simple equipment, convenient, fast, saving material, high efficiency, low cost, simple operation, the application come to more fields like mine engineering, civil engineering, hydraulic engineering, environmental engineering etc.High pressure jet grouting method is one of the important ways to deal with the foundation. High pressure jet grouting method's main principle is to use nozzles with a drilling rig drilling grouting tube to deep soil, and then the high-voltage equipment with the pressure of 20MPa～40MPa jet out the slurry or water from the nozzle, the jet stream impact the soil to damage it. When the big energy, fast, the pulse-like jet stream over the dynamic pressure of the structural strength of soil, the soil particles falling down from the whole. Part of the small size of the soil will out with the ground water or serous. But the remaining soil in the jet stream impact, centrifugal force and gravity, will mixing with the slurry mixture, and rearrange regularly in the principle of a certain proportion of the slurry and the quality of soil. After serous solidification, the layer formed in a body of cement-soil consolidation in order to achieve the purpose of strengthening the foundation.From the high-speed jet stream and fluid dynamics characteristics of the mechanism of grouting and consolidation of high-pressure injection of the basic physical traits and its influencing factors ,using high pressure jet grouting technology to design and construction the foundation, this paper research the high pressure jet grouting technology and the basic principles of reinforcement foundation.Based on a high-rise residential building project, studied the high pressure jet grouting application in the gravel layer. Reference to local geological conditions, construction equipment, routing materials and engineering experience, a reasonable technology parameters of high pressure jet grouting and the holes' locations selected, the design executed. At the same time, this paper discusses the construction of high pressure jet grouting process, quality inspection and construction issues attached to more attention. Through the load test, indicating that high pressure jet grouting reinforcement in the gravel layer in the design of the foundation is successful.Finally, using ANSYS procedure to executed numerical simulation of the single pile in gravel layer .Based on reasonable material parameters, the settlement characteristics of deformation and force numerical simulation are accurate relatively. Through the numerical simulation to verify the design of the high pressure jet grouting pile is reasonable, reasonable optimization of pile spacing ideas is suggested also.This article's research on the high pressure jet grouting, especially the selection of reasonable design parameters, construction techniques and finite element numerical simulation of the gravel layer ,has important theoretical meaning and significance in using high pressure jet grouting technology in this geological conditions.