Anti-sliding piles have good reinforcement effect in slope under earthquake. In this study, new combined piles are proposed, and models of bedding rocky slopes with different weak interlayers are established. The force characteristics, reinforcement mechanism and effect of the combined piles are analyzed. The main findings are as follows: the different mechanical mechanisms of the slope reinforced by the flexible and rigid combination of piles result in different deformation patterns; through the pre-stress of the horizontal connection structure, the h-shaped flexible structure connecting the double-row piles can reasonably distribute the squeezing pressure and shear force on the piles to realize the synergistic seismic resistance of the piles, and its reinforcement effect is better than other piles. Based on the above findings, the study of combined piles for reinforcing rocky slopes has important engineering significance.
In recent years, the destabilization failure of stratified rocky slopes caused by earthquakes is a common and serious phenomenon, which has become a research focus in the field of geotechnical engineering and engineering geology (Guo et al., 2017; Song et al., 2018 and 2020). In order to solve the deformation and failure of rocky slopes, a lot of research has been conducted on pile reinforcement methods (Liu et al., 2013; Lai et al., 2014; Zhao et al., 2017; Feng et al., 2018; Ma et al., 2019; Huang et al., 2020; Wang et al., 2020; Li et al., 2021). The reinforcement mechanism and effect of single-row piles, double-row piles, anchor-tension piles and crown-beam piles on supporting slopes are comparatively studied from the aspects of piles’ own structure, spatial distribution and combined structure. Liu et al. (2013) and Lai et al. (2014) showed that double-row piles are more effective than single-row piles in reducing the ground vibration response of slopes and preventing the high slope landslides in strong seismic areas. Ma et al. (2019), Huang et al. (2020) and Wang et al. (2020) analyzed that the pre-stresses applied in the anchor cable can effectively suppress the displacement of pile top and improve the bearing capacity of piles, which is better than the seismic performance of single-row piles on reinforcing slopes. In particular, the use of optimized multi-anchored piles to reinforce the slope can effectively solve the failure problem of anchor-root and improve the seismic performance of pre-stressed anchored piles (Feng et al., 2018). Piles with crown beam on top of the pile can be divided into single-row piles with crown beam and multi-row piles with crown beam. Zhao et al. (2017) and Li et al. (2021) found that the crown beam connection on top of the piles can strengthen the pile connection and improve the overall bearing capacity of the anti-sliding system, and the reinforcement effect is much better than that of single-row piles. However, there is still a lack of research on the reinforcement methods of piles for bedding slopes containing weak interlayers, especially the force mechanism and reinforcement mechanism of combined piles under earthquakes. This study aims to propose several new combined support structures, compare their reinforcement effects, and analyze their reinforcement mechanisms in rocky slopes containing weak interlayers.
