Analytical solution of active earth pressure considering soil arching for cohesive soil

The retaining wall is a common retaining structure that has been widely used in road engineering. Active earth pressure acting on the retaining wall is an important index for the design of retaining wall in engineering. In order to further improve the calculation accuracy of active earth pressure, rigid retaining wall under influence of multiple factors was selected as object of this study, and effects of inclination angle of retaining wall back, internal friction angle and cohesion of backfill, wall-soil friction angle and adhesion, and surcharge were considered at the same time. Effects of soil arching was considered by assuming the shape of soil arching behind the retaining wall was a circle shape, and the formula of distribution of active earth pressure, resultant force and inclination angle of slip surface were theoretically derived based on thin-layer element method. Validity of theoretical method proposed in this study of active earth pressure was verified by comparing results of this study, model test and existing theoretical solutions. Results show that distribution of active earth pressure shows non-linear characteristic attribute to consideration in effect of soil arching. Earth pressure increases with the increase in wall height and surcharge, and it decreases with increasing cohesion. Earth pressure increases with increasing inclination angle of retaining wall back at wall height from 0 to H/3, while it decreases with increasing inclination angle of retaining wall back at wall height from H/3 to 2H/3. Distribution of earth pressure transforms from linear to non-linear when wall back is transformed from smooth to rough. The rougher of retaining wall back and the higher inclination angle of wall back, the more obvious of non-linearity in distribution of active earth pressure. Calculation process of active earth pressure becomes complex as increase in factors, but the error of calculation results of earth pressure is smaller because the calculation conditions are closer to the actual working conditions. This study establishes a general calculation formula for active earth pressure considering multiple factors, which can provide theoretical guidance for the design of retaining wall under actual complex engineering conditions. © 2023, Central South University Press. All rights reserved.