## 1 Introduction  
Landslides widely occur in the Three Gorges Reservoir Region in China [1; 2; 3; 4]. Stabilizing piles, acting as retaining structures subjected to lateral loading, are widely used to improve the stability of the slopes and prevent their excessive movements [5; 6; 7]. The majority of studies in this field have, however, focused on the analysis of stabilizing piles embedded in homogeneous bedrock [8; 9; 10; 11; 12; 13; 14; 15; 16; 17]. From the in situ monitoring and testing of piles [18; 19; 20; 21; 22], researchers realized that the bedrock in the region are mainly multilayered rather than homogenous. This has later been validated by the exploration of the landslide sites [23; 24]. During the past two decades, several researchers studied the response of stabilizing piles embedded in multilayered media subjected to horizontal movements. [PERSON] and [PERSON] [25] numerically studied the effects of a weak and liquefied soil layer beneath the slope on the response of piles and pile groups using FLAC\({}^{\text{3D}}\) software which is a simulation software developed by Itasca company. [PERSON] et al. [26] conducted a study on the response of reinforced concrete piles under horizontal loading in multilayered soils composed of silty sand and sandy silt. [PERSON] et al. [27] proposed a semi-analytical method for the analysis of pile groups embedded in multilayered elastic soils. [PERSON] et al. [28] studied the response of laterally loaded piles in multilayered elastic soils using a separation-based continuum model. Laminarrock mass structures have generally been modeled as equivalent homogeneous or horizontally layered bodies in the analysis of stabilizing piles [29]. The Jurassic formation is most widely distributed in the slopes of the Three Gorges Reservoir area, and the number of landslides developed in this formation accounts for 67% of the total landslides in the reservoir area. There are a large number of soft (mudstone) and hard (sandstone) layers interbedded in the structure of the bedrock in the Jurassic formation in the Three Gorges Reservoir. The formation structure is different from the homogeneous rock mass, and a shear stress concentration occurs frequently under gravity loads, resulting in the overall failure of the weak layer. Therefore, it is extremely easy for the formation to slide, which leads to landslide disasters that urgently need to be controlled. Compared with the homogeneous sliding bed, the soft and hard interbedded layers change the rock mass properties of the sliding bed, and the mechanical and deformation characteristics of the stabilizing piles are inevitably affected. At present, there is a lack of landslide stability evaluation methods and control measures for slippery formations; generally, conventional stabilizing pile design methods were used to control landslides. However, the influence of the rock mass structure and the soft and hard rock layer properties on the mechanical and deformation characteristics of the piles were not considered comprehensively. The selections of the parameters had large randomness, and the analysis results obtained were likely to be inaccurate or even wrong. It is essential to study the effect of the soft and hard interbedded layers of bedrock on the mechanical characteristics of stabilizing piles. Conducting experimental analysis is an effective way to investigate the behavior of stabilizing piles [2; 3; 6; 30]. Several laboratory physical model tests [31; 32] and centrifuge model tests [33; 34] have been performed to study the response of stabilizing piles in homogenous slopes. [PERSON] et al. [35] conducted large-scale physical model tests based on a colluvial landslide to determine the variation of pressure along the lengths of anti-sliding piles. [PERSON] et al. [4] examined the behavior of stabilizing piles at different locations in the bedrock with a hard upper layer and a weak lower layer.