| Horizontal jet grouting has been successfully used in a variety of preliminary support of the weak bad formation of reinforcement in foreign countries. In recent years, the high pressure jet grouting technology level has been widely applied in domestic weak wall rock tunnel, this technology is on the basis of conventional jet grouting technology, developed a new stratum reinforcement construction technology, If measures are not in place, not only endanger the construction safety, and even affect the safe operation. Advanced pre-reinforcement technology not only can improve the strength and the stability of surrounding rock of soft, more important is can guarantee on the premise of safety efficiency and successfully complete the construction task. In order to overcome the groundwater enrichment of silty sand layer difficult technical problem existed in construction of surrounding rock, adopt advanced level jet grouting technology, within the tunnel on weak water silty sand stratum pre-reinforcement in advance. Reinforcement of concretion body not only can improve the strength of rock mass around pile, and the anti-seepage effect has played a very good. This technology successfully resolved TaoShuPing tunnel construction problems that exist in the aqueous silty sand layer, has broad application prospectsIn this paper, based on LAN yu railway TaoShuPing tunnel project, through study on characteristics of tunnel engineering rock mass, the advance of horizontal jet grouting pre-reinforcement technology and stability constraints for a preliminary analysis, the main contents include:1?Analyzed the tertiary silty sand layer in the water environment, the causes of composition, structure, diagenesis degree, and the tunnel after excavation, the stability of surrounding rock is poor, large deformation, extrusion, collapse, plasticizing, rheological, even the gushing sand, the root cause of the phenomenon of water.2?Advance guard of horizontal jet grouting pile technology mechanism, as well as the analysis of the technical scheme of horizontal jet grouting pile, summarizes the construction characteristics of the method, process flow and parameters control, site construction common problems and processing measures, finally analyze the horizontal jet grouting effect horizontal jet grouting pile has a better economic efficiency, and the stability of surrounding rock stability has played a good role.3?Through analyzing different monitor section, the section of surrounding rock stress, contact pressure, two lining steel bar stress value were under pressure range, using horizontal jet grouting pre-reinforcement in advance, the deformation of surrounding rock and convergence value decreased, the effective control of the tunnel water seepage. |
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