The Art Of "One Pile Three Uses" And Its Application

The 21st century is the century for the development of underground space. Excavation protection, as a necessary project in underground space development, the task of its system comes to an end in common practice when the excavation project is finished. However, if the system can be recycled, great economic returns will be brought about. This dissertation tries to explore the technique of "one pile three uses", which is designed to recycle the sheet piles used often in the inshore soft ground areas so as to reduce the development cost of underground space. This theme is subsidized by 98' new technique extension project in Zhejiang Province (project number: 9811) and science and technology develop project in Hangzhou (project number: 98124B26).By "one pile three uses" we mean that the sheet piles can be used as engineering piles to endure the upper structure load or as resist float piles in the basement besides being the protection structure in the progress of excavation. And at the same time, the sheet piles and the basement walls are combined to form a combined structure to resist the earth pressure. This technique involved problems about excavations protect, pile groups calculation method, combined structure calculation method and its construction techniques.In the thesis introduces the main functions and compute ways of fender piles at the first project stage of excavation, which include the protection system's force, its steel assembles and structure desire, its stable analysis and the optimization design of the excavation. Based on the preceding research, discusses intensively the calculating ways of the fender piles at the second stage when they are used as engineering piles. This includes the analysis of the single pile force, the calculating ways of the pile groups when the fender piles are distributed on strip bars, how the fender piles and the engineering piles can work together when their lengths and diameters are different, and how to calculate the fender files as resist float piles. This study deducts a formula that calculates the settlement of pile groups of different lengths and different diameters with the pile bottom settlement taken into'Consideration. At the same time introduces the computation of the transmitting force structures such as brackets. Deducts the calculation of the fender piles as a structural part of thebasement walls at the third stage, which includes the elasticity theory resolution and FEM resolution of the combined structure of the fender piles and the basement walls under the surface load and the earth pressure.In this thesis introduces some construction technology related to the problem of "one pile three uses", mainly discussing the pile-wall combination technology and the making of basement waterproof. In the last part of the thesis, this study analyzes and summarizes the data collected in an experimental project that adopts the new technique of "one pile three uses", and evaluates its economic gains. The actual data indicates that the technique of "one pile three uses " is feasible and it will bring about great economic returns.