Analysis Of Working Properties Of Composite Ground Under Flexible Foundation

With good economy and practicality, the composite foundation has been widely used in the composite foundation under embankment or flexible load. Both the theoretical research and the testing results indicate that much difference exists in the composite ground under the flexible and the rigid foundation. At the present, there are two types of settlement computation methods for the composite foundation under flexible foundation. One is the numerical analysis method and the other is the analytic method. The numerical analysis method is of some advantages. But it is not convenient to apply in engineering practice and it is hard to quantificational analyze. As a result, a convenient analytic method is needed.Considered of their coupling with stress and deformation, assumed that the settlement is two-dimensional that is considering relative slippage between the pile and soils as well as asymmetric settlement of the same depth, and the load transfer laws and deformation characteristics of embankment, cushion, piles and soils are analyzed and the solution equations of pile-soil stress ratio and settlement deformation are deduced.In addition, adopting analysis method of the composite foundation under flexible embankment that this paper works out, analyze the basic example ,the effects on the properties of pile-soil stress ratio, settlement, position of neutral point, axis stress of pile , penetration of pile ends , distributing of soil stress , distributing of compressive deformation of stabilized layer and so on are analyzed by changing depth of fill, fill modules of compressibility, cushion modules of compressibility, replacement ratio, pile size, soil modules of compressibility between piles, underlying soil modules of compressibility and pile modules of compressibility, etc. And the analyzing results will provide some reference to the engineering practice.Analyze two engineering cases and compare with static test. the rationality and applicability of the method brought forward in this paper are proved by it.