Generalized solution to active earth pressure exerted onto retaining wall with narrow backfills

The finite element limit analysis (FELA) method is used to interpret the active failure mechanisms of retaining wall with narrow backfills under translation mode. It is found from the numerical results that multiple slip surfaces will be developed in the narrow backfills in rebounding form. Moreover, the numbers of slip surfaces in various cases are summarized. Afterwards, based on the active failure mechanisms, the backfills are divided into the upper non-sliding zone and the lower sliding zone. Considering the soil arching effects and the horizontal shearing between adjacent elements, the concept of curved soil-layer element is introduced to calculate the earth pressures in non-sliding zone. The sliding-wedge method and the finite difference theory are further used to estimate the active earth pressure taking the number of slip surface into account. Also, the solution to the active thrust and its application point are deduced. The proposed analytical solutions are validated through the comparisons against the previous studies. Finally, the parametric studies considering the effects of aspect ratio, soil friction angle and wall-soil friction angle are performed. The results show that the number of slip surface significantly affects the distribution of the active earth pressure, and using the proposed analytical solution is beneficial to an economic design of retaining wall with narrow backfills.