Theoretical Analysis And Software Development Of Piled Raft Foundation Based On Interaction

Piled raft foundation has been one of the important foundations of high-rise buildings. People have established some analytical models of raft and pile-soil structure by academic researches and field measurements, and influences of the rigidity of foundation and subgrade on the whole structure are realized as well. However, theories are not mature enough when involved with the interaction among piled raft, soil and upper structure. So it will need further studies. Moreover, the development of coherent software will be greatly practical to the design of piled raft foundations of huge buildings.In this paper, functions of existing software about pile caps for individual columns are compared, primary theories of existing FEM computation software are contrasted, and the research achievements of structure-foundation-soil interaction theory are summarized. Based on this, appropriate analytical models are chosen and the coherent software is developed. The calculation of one project is also used to validate the rationality of the chosen theory and parameters. The main contents of this paper are as follows:1. Software about pile caps for individual columns based on applicable codes is developed. Caps with different number of piles(less than twelve) can be calculated. Lots of functions are realized, such as the calculation of bearing capacity of single pile according to both Shanghai codes and country codes, the checking of bearing capacity of pile groups, the checking of die-cut and shear resistance of caps, the calculation of moments and reinforcements of caps, the checking of crack of piles and the calculation of settlement of the pile foundation. In addition, the analysis of some examples is also used to validate the rationality of the software.2. The theories of interaction are summarized and analytical models of raft, pile-soil and superstructure are settled respectively. Moreover, primary theories of existing FEM computation software are compared. Based on this, appropriate models are chosen for our FEM software. Sub-structure method is used for superstructure...