Study Of The Work Property Of Pile-net Composite Foundation

Pile-net composite foundation is especially suited for soft foundation treatment, its characteristics is that pile and soil share the loads with the cooperation of piles, soil and net. It has many advantages, such as small settlement, ease controlled post-construction, high stability, no precompression, shorten construction, and so on. We can disposal spare piles on the crude foundation by scientific and rational design, cut down the number of piles and construct cost, which is fit for railway, highroad, city roadway, large-scale dam and fill project with the tremendous economy benefit. Pile-soil stress ratio is basic notion and calculation index in composite foundation; it points out pile and soil stress distribution, and it need be used both in settlement and bearing capacity calculation. According to the composing of the pile-net composite foundation, reducible model of composite foundation is established; then, based on force balance condition of net unit and the characteristics of embankment loads, the formulas of pile-soil stress ratio and post-construction settlement are deduced; at last, main factors that influences pile-soil stress ratio and its rules are analyzed quantificationally. For further studying bearing performances rules of pile-net composite foundation influenced by main parameters, such as geosynthetics, cushion thickness, pile strength, space between piles, loads magnitude, numerical simulation experimentations are carried out on the bearing performances of pile-net composite foundation by using the finite element method (FEM) software of ABAQUS. Rules are obtained that diversified factors influence performances of pile-net composite, which includes pile-soil stress distribution, pile-soil stress ratio, reinforce area settlement and roadbed lateral displacement. At last, optimized design method of pile-net composite foundation is discussed based on the numerical simulation result.