The Adaptability Of Construction Methods For Underground Cross In Flight Area Of Soft Ground

With the development of economy, underpass is applied for airport extension under operation condition in more and more airport, and the most difficult is the one that is constructed in soft soil stratums under flying area, all construction methods not only should adapt to the soft soil stratums condition and route condition of flying area in airport, but also meet the strict requirements of environment and safety. The adaptability of several construction methods under complex condition in flying zone is studied in this article, and main study content and fruit as follows:(1) The adaptability of shield method, pipe-roofing method, shallow-depth subsurface excavation method and cut-and-cover method is studied from five aspect, these aspects are adaptability of stratum, adaptability of environment requirement, adaptability of route restrictive condition, adaptability of construction period and cost and adaptability of safety control. And the adaptability of every construction method in soft soil zone is compared.(2) Ground settlement, stress of pavement, slope ratio of pavement and distortion curvature of pavement are studied by using of experienced formula and numerical calculation on condition that shield method and pipe-roofing method are applied for underpass in runway zone. Quantitative analysis is used for the adaptability of two kinds of methods in strict environment requirement zone, and the conclusion is shield method is more suitable for strict settlement control zone in the condition of present parameter control level, but deeper depth and strict control measure still be needed.(3) The factors of construction settlement control index are summed up on the basis of analysis on calculation result. And a conclusion is get that maximum settlement control standard is not only related to strength of pavement, thickness of pavement and soil property, but also related tightly to existed settlement of pavement and construction settlement curve. Pavement stress control theory is applied for control standard calculation of underpass with shield method in runway zone.(4) Shield method, pipe-roofing method, shallow-depth subsurface excavation method and cut-and-cover method are studied by being combined with engineering practice of one airport in SHANGHAI, the conclusion is reached by comparison that...