The Technique And The Application Of High Jet Grouting

High pressure jet grouting technology has remarkable characters of wide range in scope, convenient for construction, safety, high pile shaft strength, abundant material, lower price and so on. So it is widely applied in consolidation of building foundation, foundation treatment, anti-seepage or impermeable, stability of slope, impermeable dam, etc. it has been spreaded over the world.The paper analyze the classify and characters of injection grout technique, detailed research the mechanism, type, character and the application in geotechnique in summarizing the development and application of grouting technique of the world.The paper detailed study the characters, major construct process parameters, serum material, the applicability stratum range, operation mechanism in foundation reinforce, the effect in foundation treatment, key technical parameters and the design calculate. This chapter describes the detailed construction process, such the as applicability stratum range, determination of construct parameters, quality inspection. In view of the first-class highway common surface crack question, through analysis the surface crack reason, the paper elaborated the application of the sole pipeline high pressure grouting in the transformation project with surface of 222provincial NanXu roads, after the roadbed construction, the road surface appears the longitudinal crack or the transverse crack nearby the K3+550 and the K3+650 section, crack opening 20mm, the road surface average subsidence has approximately reached 18cm, the biggest subsidence is bigger than 30cm, and exists the tendency which continues to develop, for more than an traffic operation year, the road section roadbed stably after the sole pipeline high pressure spurts processing, the reinforced effect is remarkable, and achieved the anticipated target, the drilled core sample of 23 high pressure piles from the center 200mm are all integrity and compact, which indicated that grouting under the pressure of 20MPa spurts the weak soil layer, the pile diameter is bigger than 600mm. The practice and the research indicated that, the sole pipeline high pressure grouting have the construction machinery facilely, the construction craft is simple, in the depth portion weak foundation soil reinforcement, if correctly used the construction parameter, the optimized construction order, it would controlled effectively the covered soil layer not to be perturbation and destruction.In view of common broken pile question of the drill hole pours pile, with the comprehensive comparison of common accident processing, the paper elaborated the application of the high pressure grouting technology on broken pile processing in a large bridge pile foundation project of north Jiangsu, in the project the host bridge pier pile's diameter is 2.5m, effective pile long is 85.0m, in process of pouring concrete, an accident caused broken pile, by the thorough analysis accident factor, we applied the processing plan of " high pressure spurts cutting + premium mud clear hole + high strength cement mortar replacement + pouring concrete", as a result, the drilled core sample is complete, the concrete compressive strength value achieves 31.93MPa; After the sound wave transmission examination, the acoustics parameter in the broken spot of various section haven't exceptionally, the average wave velocity reaches 4150m/s, meets I kind of pile design requirements.