Under the action of vertical loading, batter piles rarely appear individually, as they undergo horizontal and vertical displacements at the same time and produce a sizeable additional bending moment. However, previous studies have mainly focused on a single batter pile, which is inconsistent with engineering practices. Although single pile tests can easily reveal its working behavior, they also ignore two important factors, namely, the internal force redistribution caused by the deformation limitation of the mirror-like pile, and the interaction between the symmetrical piles and “clamped” soil (the soil between two symmetrical piles). Therefore, this paper took symmetrical batter piles as the test object to explore the influence of the two factors on the load transfer mechanism. Moreover, the deformation mode, distribution of inertial forces, and group effect of symmetrical batter piles were also discussed. The results showed that the “clamping effect” caused by the pile deformation had a significant impact on the load transfer. Under vertical loading, the flexible symmetrical floating batter piles were the only deformation mode. Under the constraint of the cap and mirror-like batter piles, the symmetrical conformation partially compensated for the disadvantage of the additional bending moment.

When the finite element-strength reduction method is used for two-dimensional slope stability analysis for elastic-perfectly plastic material, the failure criterion usually adopts the criterion of plastic zone penetration. That is, when the slope is in the limit equilibrium state, the plastic zone goes through the slope from the toe to the top. Meanwhile, the critical slip surface is composed of a series of points of maximum equivalent plastic strain along the depth direction. By deploying a set of parallel lines approximately perpendicular to the slope surface and picking out the points of these lines with the maximum equivalent strain points, we obtain a series of points taking on a wave shape, which constitutes a signal function. Subsequently, the wavelet packet analysis is used to smooth these points, i.e., locating the critical slip surface. The analysis of classic examples and comparison with Spencer’s method show that the proposed method in this paper is reasonable and effective.