Application And Management Of Piles Construction Technology In Deep Soft Soil Foundation Of DFDQ Project

Soft soil foundation is widely distributed in our country, especially in coast area. Soft soil has the property of high water content, big void ratio, low shear strength, small permeability, obvious rheology and thixotropy. The most used method for heavy industrial buildings and high-rise buildings is adopting pile foundation through deep soft soil layer with the purpose to improve the bearing capacity and reduce the settlement. It is more difficult to construct static pressure pipe piles and bored piles in soft soil than any other soils.In this paper, the constructions of ground static pressure piles and cast-in-place piles under walls and columns in DFDQ Project are considered. A series of analysis of quality control and safety management is done with the theoretical basement of project management and economics.The returning soil amount and the effect of self-guiding hole to it are analyzed combined the DFDQ Project. A new opening zigzag patent pile tip is developed and applied. The comprehensive construction technical measures of prevention and control of soil squeezing effect is put forward from the aspects of construction direction, pile sinking speed, set of anti extrusion ditch and stress release hole. The displacement and pore water pressure are monitored in the process of pile sinking. It is proved that the above measures are effective and the construction quality of static pressure piles is controlled.The engineering difficulties are analyzed for bored piles construction in deep soft foundation in this paper. The pore size, pore forming method, pore forming process and construction technical parameters are controlled. The technical measures such as rising the specific gravity of slurry in soft soil foundation is put forward and the hollow bell shaped streamlined pile hammer is developed and applied. Through the application of patent pile hammer and a series of technical measures, the collapse and necking problems of holes are avoided and the construction quality of bored piles is improved.Finally, the quality, schedule and security measures are summarized from the aspects of system, personnel system, materials, equipment and environmental management in this paper. These measured are applied in the project and it is proved that good results are achieved.Through case study, a series of technical and management measures of constructing cast-in-place piles and static pressure piles in deep soft soil foundation are summarized, which can provide reference for the following projects. The application prospect of this research is very broad.