# Calculation of Nonlimit Active Earth Pressure against Rigid Retaining Wall Rotating about Base
## 7 Conclusions  
1. The primary stress traces in RB of retaining walls were utilized for calculating earth pressure in this study. The effect of the soil arch effect on the deflection of the principal stresses was considered, and a curved thin-layer cell method was employed to characterize the inhomogeneity of the stress distribution at the interface above and below the cell. A rigorous theoretical derivation was also performed.
2. The notion of friction angle developed value was leveraged in this study to develop a nonlinear relationship between the mobilized value of the friction angle and horizontal displacement of the soil to characterize the stress state of the soil behind the wall under nonlimiting situations. Parametric analysis indicated that the closer the soil was to the top of the wall, the higher the friction angle developed value, provided that the wall rotation was a constant.
3. The analytical solution of the soil pressure strength derived in this paper was compared with the model test data for validation, and the agreement was good. This verified the rationality of the proposed theory. The active earth pressure strength  
Figure 8: Effect of rotation angles on the effective value distribution along wall depth of (**a**) soil friction angle \(\varphi_{\text{m}}\) and (**b**) interface friction angle \(\delta_{\text{m}}\).  
increased monotonically with depth within the wall height in RB. The earth pressure intensity exhibited a linear variation in the upper half of the soil but a stronger nonlinear distribution in the lower half. (4) The earth pressure intensity distribution decreased as the angle of rotation increased, as revealed in parameter sensitivity experiments. Upon reaching a certain angle of rotation, an inflection point in the earth pressure intensity distribution curve was observed due to the upper soil reaching ultimate equilibrium while the lower soil remained in a nonlimiting state. If the rotation angle was fixed, the horizontal earth pressure strength increased and then decreased as the interface friction angle increased. (5) Engineers can use the monitoring data of the retaining wall to judge the displacement mode of the retaining wall and select a reasonable calculation method. (6) This paper on can provide a reference for soil pressure calculation for rotating walls, but the study had some limitations. First of all, it was assumed that the fill behind the wall was of the same nature, without consideration of layering according to soil properties. Secondly, the study was only for the condition of sandy soil. Further research is needed on the earth pressure of rotating walls with cohesive fill soils. Last but not least, reinforced walls and geosynthetics are always used in practical projects. We will study this field in depth in the follow-up work.  
Data curation, Z.W.; Funding acquisition, X.L.; Methodology, Z.W.; Project administration, Z.W.; Supervision, W.W. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. Not applicable. Not applicable. Not applicable. Not applicable. Not applicable. The authors declare no conflict of interest.