The Theoretic Research Of The Pile-Cap Considered The Interaction Of Soil-Pile

Supervised byln this paper, the theoretic research of the pile-cap considered the interaction ofsoil-pile is introduced, which is the subsystem of The Research of Theory andMethod in Optimized Design of Strip Beam Supported on Piles, financed by Hunanprovince's Science Foundation.The load of the foundation of pile-cap related with not onIy the load of upperstructure, the strength of material, the style of structure, the rigidity of pile etc., butalso the variable soil, as fOrms a cornplex system. Its behavior and defOrmation havenot been understood very well until now, therefore, the present method of design isnot perfect. Moreover, it has defect in safety of the structure and economy ofconstruction, which need further research. So, the theoretic research of the pile-capconsidered the interaction of soil-pile is done in this paper.Based on the load transmission mechanism of space truss, and referenced theanalysis of test materials, a formula for calculating the bearing capacity of reinforcedconcrete compression strut is introduced. By using the theory of plastic hinge-line, anupper limit solution of bent bearing capacity for four-pile cap, which coincidesprecisely with the practical measurements, is obtained. By utilizing the reaction ofthe soil under cap and by basing on the method of plastic ultimate analysis, an upperlimit solution of punching shear bearing capacity for pile cap is acquired, which. coincides precisely with the practical measurements, and the formula is similar to thecode.A brief discuss on cooperative work of strip beam of foundation and single rankof piles is made. Separately considering the pile-cap and the pile-group, thencoupling their matrix of rigidity, the inner force of pile-cap is solved by the numericalmethod under some reasonable supposition. In comparison with other method, thecalculating results are exact, reliable and convenient in using. The method provides apowerful tQol fOr further analysis and research on this kind of structure.