Study For The Earth Pressure And Side Friction Acted On The Open Caisson's Wall In The Loess Region

This article firstly summarizes the general situation of the single rectangular open caisson, and then narrates the structure and layout of the open caisson from the view point of design and the existing theory of design and calculation and the calculation of the main components. It mainly analyzes and studies what a role the determination and selection of earth pressure play in the whole process of design and calculation of the open caisson. This article also describes the calculation method of the loess region open caisson wall earth pressure and side friction in the existing design and calculation theory and its scope of application, emphatically indicates its existing problems and shortcomings.Then, this article takes Xi'an Transportation Item North SanHuan Rainwater projects as the research object, and makes a real-time monitoring for the entire sinking process of the open caisson. According to a large number of site measured data, the article deeply analyzes what a relation the measured earth pressure has with the active earth pressure and the static pressure, describes the limitations of theory that the open caisson wall suffers the active earth pressure used in the loess region, obtains the size and distribution of the earth pressure of the open caisson wall at different depths in the loess region and simple calculation methods and empirical formulas, brings forward a new earth pressure distribution model of the equivalent cross-section open caisson exactly accord to the actual earth pressure.In addition, in order to research and found the law of the change of the open caisson wall earth pressure and side friction at different depths in different stratum when the open caisson is sinking in different types of sedimentary strata, develop and improve the well-sinking technology and method and the design and calculation theory in Xi'an regions, this article expands the friction characteristics study of the reinforced concrete slab and different types of soils through large-scale direct shear test. This article deeply discusses the friction coefficient on the contact facet between the open caisson wall and the earth around it which is affected by the soil water content and density and other factors. Thus the empirical formula for calculating the open caisson wall side friction can be gotten. The conclusion can be learnt for the similar projects as well as a reference.