The Application Of Stone Flour CFG Pile In Ninggdao Expressway

Highway is the inevitable product of economic development, but also the basis for national economic development, its construction should meet the need of fast, safety and comfort.Be considered for the fast, highway is generally designed as straight line between the two site, which inevitably will go through some of the complex geological region; be considered for the safety and comfort, when the highway go through the complex geological areas, the complex geology should be proper handled to minimize the bad impact of expressway operation.Because of the unique geographical location and geological environment, there are a lot of silt, silt loam, silty clay and other adverse geology in China's coastal provinces and Jiangxi, Hunan, Hubei and other places. And the construction of the highway will inevitably pass these areas. Researcher of the engineering and academia have studied the treatment of soft soil foundation for ten years, and gradually improve and develop the ground processing technology, and achieved fruitful results of theoretical research and practice.One of the research is the CFG pile technology which was used in the field of construction project,As the convenient construction, easy to control the quality, the deeper depth of reinforcement, can effectively reduce the settlement after the foundation and substantial increase the bearing power of the foundation and other technical superiority, The CFG pile technology is gradually application and promotion in Soft Foundation Treatment.The research of stone CFG piles is got improved from the traditional CFG piles, according to the treatment of soft soil of Ningdao expressway, the main study is focused on the pile material, pile design, construction, testing and finite element analysis. The research work is divided into the following areas:1,in the research of pile material, according to the physical environment,the construction of filling pile by vibrosinking pipe is used. Under this construction method ,the research is on feasibility of the the pile material is stone flour instead of fly ash piles.2, according to the actual regional geological conditions of the processing area, the corresponding reinforcement planswere designed. 3, According to the comprehensive consideration of the construction method of CFG pile and the construction environment, the construction of filling pile by vibrosinking pipe which is more simple lower cost is used.4,After the construction, the load test which is recognized as the most direct and most reliable in project is used to test the bearing capacity of piles, and test results are analyzed to determine whether it can meets the engineering requirements of its capacity. 5, Through the finite element analysis software ANSYS, the actual pile the forces is simulated, the finite element of the pile settlement and stress analysis are carried out.This study is based on the flexible foundation of freeway, and its force situation is different from the rigid foundation of the buliding construction. Meanwhile, with the large-scale of freeway construction, the quality of engineering have become increasingly demanding, and the problems encountered is more and more complex. So it is necessary to give the further research of the soft ground treatment of CFG pile.