Research On Grouting Treatment Of The Soft Soil Foundation Reinforcement In Langcang Freeway

Recent years, different measures have been used to deal with the soft soil foundation in freeway construction. Usually it has limited construction time, and some problems is discovered during the constuction. Therefore, treated the soft soil foundation directly and quickly has become increasingly important. In central of Hebei Province, the geomorphological characteristic is alluvial plain. The hard crust is widespread in the soft foundation of this area. It is imperative to reinforce the soft soil foundation quickly, improve the mechanical strength and deformation modulus of the soil, reduce the total settlement, meet the enbankment settlement and stability of freeway. According to the period requirement and construction conditions, used grouting method to treat three sections of this freeway. Until now there are few people who used this method to treat the soft soil foundation without disturbed its crust, so, the correponding experiment has been done on this method.In this study, the research background is langcang freeway of Hebei Province. Based on the analysis of the engineering geological conditions of this freeway, the grouting method has been researched systematically, and obtained results as follows.(1) Studied the engineering geological characteristics of the test section: Selected typical sections to calculate and evaluate the stability of the subgrade which based on the analysis of the geological and engineering geological conditions of the test section. According to the unfavorable conditions of a short period and the high voltage wire in the construction site, and after comparatively analysing the methods of foundation treatment, the grouting is used in this area.(2) Researched the grouting of soft soil foundation of the test section: Through implementing and researching the test engineering, proposed suitable grouting boundaries and parameters, and suitable grouting material, mix proportion and process. (3) Combined with the project fact, numerical simulation anlysis is used to study the process of grouting from methods and pressures of the grouting, and simulated the behavior of the soft soil foundation from natural state and end of grouting. Verified the parameters of grouting and the effect. The result is that the grouting has improved the bearing capacity and physical and mechanical properties.(4) Made a comprehensive evaluation of the perfermance of this construction engineering. The result showed that the bearing capacity and the safety factor have met the requirement of settlement and stability. The grouting is more reasonable than other methods in reinforcing such soft soil foundation quickly.The study not only can solve the design, process methods, contents of detecting etc. But also can provide a economically reasonable, technically feasible and rapid measure to the emergency project of strengthening the soft foundation of freeway. This control technology will provide useful reference for the future soft soil treating.