| The classical earth pressure theory mainly is the Rankine's earth pressure theory and Coulomb's earth pressure theory, or modified empirical formula based on two classical theory,which be used in the design of retaining structure.However,when the inclination angle of the inclined surface of the upper part of the wall is larger than that of the soil and the stability of the soil pressure, it is difficult to use the theoretical calculation to make an accurate solution.In view of this,the paper relys on the project of Chongqing construction science and technology to research the inclined slope under the construction of key problems of slope soil pressure calculation theory and experimental research,the research of soil behind retaining wall slope's angle is greater than the internal friction' angle of soil, erect rigid retaining wall back by the size,distribution of earth pressure and its resultant force point are analyzed,adoption of theory analysis combining physical model test and numerical simulation.The main contents are as follows:(1) Theoretical analysis mainly based on the classic Coulomb theory,and simplified theoretical calculation model( ?>? ) was established, using the limit equilibrium method for deriving, made a comparison and analysis with the existing calculation theory. At the same time analyzed the fill slope angle, angle of internal friction of soil, vertical depth and proportional coefficient to the influence of the rupture angle formula is derived; The study found that only the ratio of m(h/H) to the rupture Angle is negative, and the other is positively correlated; The effects of ? and m on ez are restricted in the analysis of lateral pressure.(2) The active soil pressure model experiment under two modes of translocation was studied by the author use the self-made test model box;Mainly the size of ? on the size of the active earth pressure, the distribution of the law and the impact of the action composition of forces point. The results show that the displacement required for the soils with different depths in the translational (T) displacement mode simulated by the translation baffle is basically the same, with the increase of displacement S, the composition of forces point of action decreases gradually; With the increase of the inclination angle ? , the synergistic point of action increases gradually, When? =70° the position of its synergistic point is about 0.4H. The horizontal earth pressure is nonlinearly distributed over the wall-to-bottom rotation (RB) displacement mode simulated by the rotary baffle, and the displacement S required for the RB mode to reach the limit state is less than the T mode.(3) The numerical model is established on the basis of the physical model,using the PLAXIS finite element software establish the numerical model. Analysis found that the displacement area of the soil after the wall is wedge with the increase of the displacement of the retaining wall, in the two displacement modes.When the slope angle ? of the slope fill surface increases, the displacement area increases gradually,and the displacement near the top of the wall is larger than the displacement at the bottom.In the RBT displacement mode, the stress can not reach the limit state at the same time behind the wall.No matter what kind of angle ?, the equilibrium point which distance is the top of the wall above 0.6m should first reach the limit,and as the inclination ? increases, the wall displacement required for the soil to reach the limit state decreases gradually.(4) Finally,the paper through the theoretical calculation,the physical model test and the numerical model comparison between each other.And gives the the formula applies to ?<? < 70° ,0.2<m<0.65. |
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