Calculation and analysis of soil stress state and active earth pressure behind retaining wall

In order to explore the stress state of the soil behind the retaining wall in the earth pressure theory and improvethe consideration of the mechanical conditions of the soil, based on the relevant research results, it was proposed that the soil element on the slip surface reaches the limit stress state, while the wall-soil interface and the internal element of the soil wedge do not reach the limit stress state, under the condition of active earth pressure. The unlimited stress state of soil was described by unlimited parameters, the problem was solved based on two-dimensional differential equation. The distribution of earth pressure on the retaining wall and earth reaction force on the sliding surface were obtained through certain assumptions, and the inclination of the plane slip boundary and the parameters representing the unlimited state of the soil behind the wall were inversely solved by further considering the static balance condition and moment balance condition of the whole sliding wedge. Thus the active earth pressure solution considering the incompletely limit stress state of the soil and satisfying all mechanical conditions was obtained. Finally, the reliability and rationality of the theory were verified by case study examples, and the effects of soil internal friction angle and external friction angle on earth pressure distribution and related parameters were analyzed. The theoretical results show that the limit stress state only appears on the sliding surface, and the soil located in the wall and soil wedge does not fully reach the limit state, and the approximate treatment of the soil as the limit state does not have a great impact on the calculation results of earth pressure. Under the same parameters, the dip angle of the slip surface calculated theoretically is greater than that of Rankine solution and Coulomb solution. The internal friction angle and external friction anglehave different effects on the distribution of earth pressure, the position of resultant force action point, stress state parameters, principal stress deflection angle of soil and so on. © 2022, Central South University Press. All rights reserved.