| under the background of the development of China’s economic boom and the sustainable development of the western region,Recently,our country western region like YunGuiChuan,etc has invested a large number of resources for the construction of infrastructure. The air transport industry development advantage is especially obvious.A large number of feeder airports started construction in different places. Part of the airport start expanding and rebuilding. Compared with the central plains region and the eastern coastal areas, Western region geological conditions are much more complex. Thus in the design phase and the actual construction has produced many special engineering problems. Such as the high fill foundation treatment, High altitude construction, High seismic intensity, Construction in extreme weather conditions,high slope, Complex geological conditions, High quality of work requirements.In the southwest mountainous area often visible high fill slope in the construction of the airport. It’s adopted by packing for local materials of rock blasting material.These packing with complex lithology large size,etc. Existing a lot of practical experience, settlement deformation controlling in high filling slope and Creep property research are Mountainous area high fill airport construction’s difficulties and main problems.In this paper,the writer take the soil form Chongqing Wanzhou high filling airport as the research object.By means of the indoor basic mechanical experiment,the theoretical analysis, the numerical simulation methods for Systematic research.The main research contents and results are as follows.(1) Through reading and study of domestic and foreign soil creep characteristics of literature, summarizes recent creep model and the research methods, and various methods of study made the introduction of the system are given, and Given its scope and the problems,follow-up study found problems that may occur.(2) By analyzing routine soil test and field data, a systematic generalization about the basic mechanical properties of the coarse-grained soil and physical indicators had been made. By uniaxial compression test, soil compressive strength, modulus of compression and other indicators are determined, which provides a referenceinformation for the subsequent consolidation creep test and creep model.(3) Combining with settlement deformation mechanism and engineering features of high-filled subgrade,doing one-dimensional consolidation creep tests for coarse-grained soil, It shows that the coarse-grained soil has obvious nonlinear creep deformation, Select a suitable empirical formula to describe the strain-time,stress-strain relationship, In the same conditions,when the degree of compaction is greater, the structural strength of coarse-grained soil is more significant and its final cumulative deformation is smaller. In addition, the creep equation with the logarithmic form of the compacted clay is fitted, the relationship between the stress and the strain of coarse-grained soil is described by the power function creep model including the influence of stress and the deformation of coarse-grained soil is explained through microcosmic angle.(4) The test results are analyzed by using composite element model of generalized Kelvin model and Burgers model. The two kinds of model parameters are obtained.Through comparing the experimental curves with theoretical data, it is found that the Burgers’ element combined model shows a better fitting effect.(5) Numerical simulation of creep sample is executed by using FLAC combined with Burgers model, the comparison of empirical formula and theoretical model is done,and the rationality of the model obtained is also verified. It can great practical value in high fill engineering applications. |
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