Study On Compacting Effect Of Fluid State Concreting For Bored Pile

With the modern civil projects developing in the directions of super-height, super-weight and super-depth, the pile group foundation composed of the Large-diameter and super-long piles are adopted by more and more projects. But people's understanding of the basic laws of this kind of large pile group foundation far lags behind the request for the engineering design, especially the study on the concreting process bring on intensive compacting effect of soil around the pile. Based on the under study National Basic Research Program of China(973 Program)—'Basic Research on the Safety of Major Engineering Project in Hazardous Environment' , National support for scientific and technological projects the 11th Five-Year Plan—'key technologies study of Sutong Bridge' and Jiangsu Provincial Traffic Science Study Program-'the Key Techniques Study on Supersized boring pile-group foundation', Be aimed at Large-diameter, long high-pile, super-long bored pile of Sutong Bridge, carry out the model test research, several problems are study as follows:(1) Based on monitor results of pile-group foundation of Sutong bridge and the unreasonable phenomenon of large diameter bored pile design, find how to research compacting effect of concreting for super-long and large-diameter bored pile.(2) Uses the scale model experiment confirm the lateral pressure of cause by pile body concrete in the concreting process. Studies the distribution of this lateral pressure and it's change form.(3) Uses the cavity expansion theory to analysis the compacting effect cause by pile body concrete in the concreting process.(4) Quantitative analysis the change of pile diameter, and study the influence to bearing capacity of this factor.(5) Quantitative analysis compacting effect of soil around the pile, confirm influence region and soil parameter changes of this region.(6) Combined the scale model experiment and finite element method to research the compacting effect, use this to test result of the cavity expansion theory.(7) Use the ABAQUS software to computer the bearing capacity of pile foundation with soil parameter change and no change.