Analysis Of The Consolidation Settlement Of Red Clay Foundation Processed By Macadam Pile In Kunming New Airport

The red clay as a special geotechnical soil has been concerned in engineering. In recent years, along with airport construction in southwest mountainous region, there are the inevitable questions of the red clay foundation treatment and the red clay consolidation settlement calculation under high fills, which are also the key questions to safeguard the airport construction security .The gravel Pile treatment method as an effective method of dealing with red clay foundation, has many advantages. This method has been used widely in the red clay of the airport, the power plant, the highway and so on. The some achievements are achieved in the reinforcement mechanism, construction techniques and design theory of the Gravel Pile Composite Foundation. But compared to the engineering practice, there is still the gap between the theoretical study and it, particularly the consolidation settlement calculation is urgently needed to further study.There are two kinds of methods about gravel pile composite foundation's consolidation settlement, analytical method and numerical method. The consolidation settlement of gravel pile composite foundation is calculated by the analytical method on the simple conditions of constitutive model, boundary conditions, and load ways, which is different to the actual condition because of some assumptions. Compared to the analytical method, the multiple affecting factors of gravel pile composite foundation is considered by the numerical method, in which the consolidation settlement of the gravel pile composite foundation can be reflected and the properties of deformation and strength of it is revealed. Hence the grounds of optimal design for gravel pile composite foundation are provided.Based on the previous research results, the before and after treatment of red clay foundation in Kunming new airport by the gravel pile composite foundation is studied as the following:â…°.The changes of physical and mechanical properties of red clay foundation before and after treatment by the gravel pile composite foundation is obtained by analyzing the results both of physical and mechanical tests in door and testing in situ. Then the engineering effect of it is also obtained.â…±.Using the finite element method, parameters, under the different permeability and compressibility of the pile ,different pile's replacement ratio ,different pile's length, different compressibility of subjacent bed, has been discussed to discover their effects on the consolidation characters of composite foundation. The distribution of excess pore water pressure, consolidation settlement have been calculated and their results are analyzed and generalized The consolidation characters of composite foundation is studied by using the finite element method to analyze the parameters under the different conditions, such as the different permeability and compressibility of the pile, the different pile's replacement ratio, the different pile's length and the different compressibility of subjacent bed. Particularly the distribution of excess pore water pressure and consolidation settlement is studied and the regularity of them are concluded.â…².The settlements both of nature red clay foundation, and the gravel pile composite foundation in Kunming new airport are analyzed by using the finite element, particularly the distribution of pore-water pressure and consolidation settlement, then the calculated results by numerical method and the results of analytical method are compared.â…³. The results of numerical simulation is compared and analyzed with the observed data and the fitting data. Then the reasonable calculation method and the parameters are selected, which is provided as the reference for optimal design of the airport later stage of construction of Kunming new airport.