Filed Test Study On Reinforcing Soft Foundation Of Bridge Approach By Low Intensity Piles Composite Foundation

In the express way construction on a soft foundation, resolving "bump at bridge-head" is a difficult technical problem. Low intensity piles composite foundation is a new method which can improve the soft foundation at bridge approaches. Now the application of low intensity piles composite foundation in soft foundation of express way is scarce and the character of low intensity piles composite foundation under embankment loading is misty. Via the practical engineering of improving the soft foundation with the low intensity piles composite foundation the field test study is done. These work is done:(1) The method of improving the soft foundation of the bridge approach with the low intensity piles composite foundation is summarized;(2) The field test method of improving the soft foundation of the bridge approach with the low intensity piles composite foundation is summarized;(3) The strain character of the low intensity piles composite foundation under the embankment load is studied;(4) The stress character of the low intensity piles composite foundation under the embankment load is studied and the differences of the pile-soil stress ration and what make them is discussed;(5) The calculating mode of bearing capacity of low intensity piles composite foundation is discussed.The results indicate that this method can minish settlement largely, decrease level thrusts on bridge abutment, make the settlements transition, improve the bearing capacity of foundation soil and its economic benefits are notable. The results of field test show that low intensity piles can put into widely use in soft foundation of express way.