Strictly speaking, high-pressure rotary jet pile is used to improve soil, that is, cement slurry is sprayed into soil layer and mixed with soil by high-pressure rotary nozzle to form continuous lap cement and solid.The construction area is small, the vibration is small, the noise is low, but easy to pollute the environment, the cost is high, not suitable for the special soil which can not make the slurry solidify.
Cast-in-place pile system refers to the pile hole formed in the foundation soil by pile machine at the engineering site, and the pile made by placing steel cage and pouring concrete in it.The former is used to reinforce the roadbed, while the latter is used to make the foundation of the bridge.
High-pressure rotojet pile is used to spray cement slurry into soil layer and mix with soil with high-pressure rotojet nozzle to form continuous lap cement and solid.The high pressure rotary jet pile should be carefully used for the foundation engineering where the velocity of groundwater is too high and the gushing water is too high for the stratum where the pebbles, blocks and boulders in the bedrock and the gravel soil are of skeleton structure.
(1) the high-pressure jet grouting method is applicable to the treatment of silt, silt soil, flow plastic, soft plastic or plastic clay soil, silt, sand, loess, plain fill soil and gravel soil foundation.
(2) when the soil contains a lot of large-size stones, hard and sticky soil, a lot of plant roots or too much organic matter, the application degree of silt and peat soil and collapsible loess foundation of existing buildings should be determined according to the field test results.Its applicability and technical parameters should be determined by high-pressure jet grouting test.
(3) high-pressure jet grouting method, for the bedrock and gravel soil in the gravel, boulders, boulders in the framework structure of the stratum, groundwater velocity is too large and has gussed foundation engineering, groundwater erosion, should be used carefully.
(4) high pressure jet grouting method can be used for existing buildings and new buildings foundation reinforcement treatment, and stop water heavy curtain of deep foundation pit at the bottom of the cover soil or water, foundation pit slope reinforcement, prevent the piping and uplift, underground large-diameter pipe enclosure and strengthening, the subway engineering of soil reinforcement or waterproof,dams, dikes,, dam body and dam base foundation seepage control river levees and building underground reservoir impervious dam engineering, etc.
