Research On The Passive Earth Pressure Of Retaining Wall Under Unlimited State Of RT Displacement Mode

With the rapid development of the economy in modern China, all kinds of large-scale engineering construction as well as some basic construction are in full swing. Retaining wall working as an important auxiliary project, has dominated the important position with its unique advantage and is widely used in water conservancy engineering, highway engineering, railway engineering,municipal engineering. So retaining wall engineering has played a role which can not be ignored in all kinds of engineering construction. Retaining wall earth pressure is an important foundation for the design of retaining wall, and it is extremely necessary to study and analyze the earth pressure of retaining wall.In this paper, the finite element software is firstly established to calculate the model of retaining wall and soil after the RT model. Secondly use segmented retaining wall displacement constraint research the limit state, through the analysis of the horizontal displacement nephogram of soil relative displacement of soil area and the relationship between various parameters, and earth pressure of retaining wall along the wall high size, distribution and reasonable pointlocation, by changing the parameter analysis with the size of earth pressure,reasonable distribution and the relationship between the point position.Combined with wall displacement to consider the influence of the friction Angle and displacement of the Rankine’s earth pressure theory calculate deformation mode under the limit state of RT improved Rankine’s earth pressure calculation formula, the magnitude,distribution and resultant force point locationof the soil pressure calculated by the formula were compared with the results calculated by finite element numerical. In this paper, the finite element numerical computation and theoretical research shows that:(1)Under the non-limit state, retaining wall around the wall to the direction in a certain rotational displacement of the wall there was some relative displacement of backfill soil area which presented inverted trapezoidal shape.Relative displacement zone size influenced by the rotation of the wall displacement ratio, internal friction angle of backfill soil and the backfill soil elastic modulus, poisson’s ratio and other factors.With the wall rotational displacement increasing, the range of relative displacement increases; Backfill soil friction Angle in the body increases, while the relative displacement zone increases; When backfill soil in the elastic modulus and poisson’s ratio increasing, the range of relative displacement increases.(2)Retaining wall deformation mode of RT of non-limit state and the size of passive earth pressure distribution rule are influenced by wall rotational displacement ratio, internal friction Angle of backfill soil and backfill soil elasticmodulus, poisson ratio, etc. As the increase of the rotational displacement,the wall body earth pressure increases, the increase rate decreases, until reaches the limit state of soil. Near the earth retaining wall displacement than when a certain,soil pressure effect is not obvious, the more distance near the bottom of the wall effect of earth pressure of soil increases, the soil pressure effect is more obvious;Displacement ratio increasing, the curvature of the earth pressure distribution curve. With increasing the internal friction Angle of backfill soil, the soil pressure distribution curve of curvature is steep; When increasing the backfill soil elastic modulus, the curvature of the earth pressure distribution curve slightly larger; Backfill soil poisson’s ratio increases, the earth pressure distribution curve.(3)Retaining wall deformation mode of RT and the size of the unlimit state of passive earth pressure force point location effected by wall rotational displacement ratio, internal friction Angle of backfill soil and backfill soil elastic modulus, poisson ratio, etc. With the wall displacement ratio increasing,the soil pressure force and resultant force point increases; When Backfill soil angle of internal friction increases, soil pressure force increases while force point decreases;Soil pressure force increases slightly, the influence on the point of force with backfill soil elastic modulus is not obvious. soil pressure force increases and force point has a slightly higher,when backfill soil of poisson’s ratio increases.(4)The size and distribution of passive earth pressure point position of RTdisplacement model in unlimit state calculateed by the improved Rankine’s earth pressure calculation formula was very consistent with the results calculateed by finite element, so it provided certain references for engineering examples.