Active Earth Pressure on Rigid Walls with Polyline Backs under the Translation Mode

Rigid retaining walls with polyline backs are possibly used in filling engineering, and some types of these walls may have better stability than ordinary gravity walls with planar backs. Aiming at the active earth pressure on polyline-back walls under the translation mode, an analytical method within the frame of limit equilibrium is provided according to the potential two slip surfaces intersected in the retained backfill. The proposed method focuses on the minimum slide-resisting factor of safety of the polyline-back wall to be the objective function, and it can be performed easily using the nonlinear programming approach. Analysis results of some examples show that the proposed earth pressure is close to those obtained using the test and numerical methods with an average error of about 15%. The platform width and the ratio of the upper to lower wall height in the counterweight wall have more obvious influences on earth pressure than the slip surfaces. The overall and local critical slip surfaces are considerably influenced by the lower-back and backfill surface inclinations, respectively. The counterweight wall is the optimum configuration for the overall sliding stability among the compared five polyline-back walls due to its outward-extending platform and positively inclined lower back. This work provides a calculation method for the active earth pressure on rigid walls with polyline backs under wall translation, which holds practical significance for geotechnical engineers or practitioners in filling engineering such as embankments. The proposed method can analytically solve the active earth pressure on different segments of the polyline back of gravity walls and the two critical slip surfaces intersected in the retained soil. As a result, the slide-resisting stability of the wall can be analyzed in the design. The proposed method can be used further to compare possible different types of polyline backs of a wall and then for the quick optimization design of the gravity wall. Analysis results of an example show that the counterweight wall is the optimum configuration for overall sliding stability due to its outward-extending platform and positively inclined lower back. In brief, this work can provide a significant reference for the practical design of rigid walls with polyline backs, such as counterweight walls and hunchbacked walls, based on the easily operated limit equilibrium methods.