Studies On Soil Arching Effect And Earth Pressure For Retaining Structure

Soil arching effect and the computation of the related earth pressure had been hot topics in geotechnical engineering for many years, but there is only a little being done so far. In this dissertation, on the basis of the studies so far available, soil arching effect and earth pressure for retaining structure are studied in-depth. The main original work is as follows:1. Circular and catenary always represent the shapes of minor principal stress soil arch between two parallel walls, but which shape should be used in the calculation of active earth pressure on two parallel walls remains disputed. Considering fully developed wall friction or partially developed wall friction, circular and catenary, the two shapes of minor principal stress soil arch between two parallel walls are theoretically analyzed. According to the shapes of soil arch, the coefficients of earth pressure corresponding to different angle of internal friction and that of wall friction are obtained, and the formula of active earth pressure on two parallel walls is derived. Analysis results show that the active earth pressures on two parallel walls obtained by selecting circular arch and catenary arch are almost same, and the former is simpler and should be selected in computation.2. Considering the effect of the angle of internal friction on the inclination of sliding plane of soils behind retaining wall, circular and catenary, the two shapes of minor principal stress arch are theoretically analyzed. According to the shapes of minor principal stress arch, the coefficients of earth pressure corresponding to different angle of internal friction and that of wall friction are gained. Using the method of horizontal differential element, the theoretical formula for active earth pressure on retaining wall, the resultant earth pressure and its acting point are obtained and compared with the Coulomb's formula, the previous methods and some experimental observations. This overcomes the shortcoming involved with existedactive earth pressure theory that consider soil arching effect but takes no consideration of the influence of the internal friction angle on the inclination of sliding plane of soils behind retaining wall.3. The finite element analysis software package, ABAQUS, is used to study soil arching effect of anti-slide pile, and the effects of factors on the behavior of soil arching effect such as pile spacing, properties of soil and interface of soil-pile are discussed in detail.4. Considering the effect of strip load on the inclination of sliding plane of soils behind retaining wall, the limit equilibrium method of Coulomb earth pressure theory is improved. Moreover, active earth pressure under limit state with strip load is studied, and the corresponding earth pressure formula obtained. This overcomes the shortcoming involved with available limit-equilibrium methods that cannot calculate active earth pressure under limit state with strip load.5. Considering the effect of displacement on active earth pressure, active earth pressure formula under non-limit state is obtained, which can be used to calculate active earth pressure under non-limit state without load or with strip load. This overcomes the shortcoming involved with available methods that cannot calculate active earth pressure under non-limit state with strip load.