## 3 Results and Discussions
### Hysteretic Curves and Skeleton Curves
#### 3.1.2 Parameters i and j of Meshing  
Figure 7 describes that the hysteretic curve of TestB-1 (i = 2) presents a prolate fusiform shape and the pier has no obvious characteristics such as the reduced bearing capacity. The hysteretic curves of TestA-2, TestB-2 and TestB-3 are bow shaped and obviously pinched. There is almost no gap in the initial stiffness of the models, but the bearing capacity decreases significantly after reaching the peak load. Regardless of TestB-1, Figure 7(a.1) shows that the bearing capacity degradation of TestA-2 is slower than that in other cases after the peak in the positive direction, but in the negative direction, the degradation of TestB-2 is more delayed. Figure 7(b.1) states that the bearing capacity of TestA-2 is slightly greater than that of the other two models. This phenomenon is caused by the asymmetry of the loading in the positive and negative directions due to the directionality of the initial loading and the Bauschinger effect of reinforcement. From the hysteretic curve drawn by the horizontal displacement and the horizontal reaction force at Node8 in Figure 7(a.2), it can be concluded that the peak load is greater and the horizontal bearing capacity decreases more obviously with a finer horizontal division. When the height-to-width ratio of each mesh is about 1, the hysteretic curve of TestA-2 at Node18 (Figure 7(b.2)) is plumper and dissipates more energy than that of TestC-1. Figure 7(a.3) illustrates that the horizontal mesh division has a limited impact on the initial stiffness, peak bearing capacity and the downward trend of capacity. However, it can obviously affect the shape of the hysteretic curve at Node18 during unloading, as shown in Figure 7(b.3). The upward depression of the curve is distinct during unloading, such as TestC-2. Therefore, it is clear that the horizontal meshing depends on that of the vertical and it has a significant impact on the hysteretic curves of different locations of the wall pier studied. Figure 6: Hysteretic curves and skeleton curves of different layer divisions: (**a**) Node8; (**b**) Node18. The discretization of layers has little effect on the results, in view of the shape of the hysteretic curve and the skeleton curve. Except for model TestB-1, the energy dissipations of other models are almost equivalent from the perspective of energy. When i = 5, i.e., \(\Delta\)h = 0.82 m, the results tend to be accurate. Referring to the plastic hinge formula of the column, \(\Delta\)h is supposed to be greater than the plastic hinge length, \(\mathrm{L_{P}}=0.5744\) m. The height-to-width ratio of mesh should be about 1 to ensure the calculation speed and accuracy simultaneously when using the multi-layer shell element model. Therefore, the mesh parameters of i = 5 and j = 34 are more reasonable in this model. There is a lot to be found in common when comparing and analyzing the hysteretic characteristics of models. The loading and unloading curves coincide in the initial stage of loading. The large initial stiffness indicates that the pier is in a linear elastic working state. With the increase in loading displacement, the pier gradually enters the elastic-plastic stage and the hysteretic curve gradually becomes plumper. The area of the curve also increases and there is residual deformation after unloading. The results of layer and mesh division of the multi-layer shell element model on the global seismic performance of the pier are relatively interchangeable, but the responses of the local position are different. Adopting the force-displacement curve of the local position is more conducive to the study of the seismic performance of the wall pier. The curves at Node8 and Node18 simultaneously  
Figure 7: Hysteretic curves of different mesh divisions: (**a.1–a.3**) Nodes; (**b.1–b.3**) Node18. demonstrate that the hysteretic curves are not completely smooth in the unloading process and present a certain pinch effect.