Reverse-dip slope(Dong et al., 2020) indicates the dip direction of the strata is against the dip direction of the slope. The reverse-dip is often considered as the favorable scenario in engineering practice, as the potential sliding surface should pass through several bedding. Therefore, the geotechnical profession pays little attention to the reverse-dip slope, and thus the corresponding studies are limited. However, a number of natural hazardous occur in recent years in relation to the reverse-dip slope(Aydan and Kawamoto, 1992; Huang, 2007; Huang et al., 2017; Martino et al., 2020). Many scholars increasingly analysis the failure mechanism of topping deformation of the reverse-dip slope(Eberhardt, 2008; Lian et al., 2017; Xie et al., 2018; Gschwind et al., 2019; Lh et al., 2020; Zhang et al., 2020; Ye et al., 2021). Terzaghi and Peck (1957) described the toppling deformation and failure characteristics of reverse-dip slopes from the perspective of engineering geology. Amini et al. (2008) considered the rock mass an inclined superimposed cantilever beam, and analyzed the bending and toppling failure modes of the layered slope, where the factors of safety between the layered rock masses were considered. Alzo’ubi et al. (2010) reported that the tensile strength mainly induces the bending and toppling deformations. Goodman (2013)defined three failure modes for reverse-dip slopes, including bending, block, and bending-block failures. (Adhikary et al., 1997; Bhasin et al., 2004; Chen et al., 2015; Zheng et al., 2019)conducted a series of model centrifugal tests to study the mechanism of bending and toppling failures of jointed rock slopes.(Alejano et al., 2010); Li et al. (2015) used discrete element method to investigate the failure mechanism of the open-pit mine, where the failure of the reverse-dip slope was defined as a complex combination of dumping failures. Dong et al. (2020) investigated the influences of lithology, dip angle and rock thickness on the anti-dipping deformation, by simulating the excavation process of the anti-dipping slope. Xie et al. (2020) analyzed the evolutionary characteristics of toppling deformation in view of the energy field.
There were many influential factors to the toppling deformation and failure of the anti-dip slope, where the influence of the reservoir level is particularly significant (Bao et al., 2019; Gu et al., 2020).Xu et al. (2005) used FLAC3D to investigate the deformation and failure mechanisms of the Jiefanggou reverse-dip rock slope, considering the fluctuation of the reservoir level. (Huang and Gu, 2017) reported that the periodic fluctuation of reservoir level and long-term immersion are the significant triggers of landslides. The previous studies of the toppling deformation and failure of slopes caused by the change of reservoir level mainly focused on the global failure mechanism of slopes. Besides, most researchers only used numerical simulations and centrifugal mode tests to analyze the deformation mechanism of reverse-dip rock slopes. Up to now, the real monitoring data have not been adopted to investigate the deformation mechanisms yet, which can reflect the actual slope deformation more accurately. According to monitoring results of the superficial slope displacement, the toppling deformation characteristics of the anti-dip slope were significantly different in different portions considering the change of the reservoir level.
Therefore, this paper investigates the deformation mechanisms of a reverse-dip slope in Xiaodongcao, Chongqing city, China, considering the real monitoring data of surface displacement of the slope. The slope displacement was superposed by the geometrical partition and the spatiotemporal could map of the displacement. Herein, the could map was obtained by the inverse distance weighting interpolation of the measured displacement using ArcGIS. Finally, this paper discusses the influence of the reservoir level on the deformation mechanism of the displacement evolution in different regions of the reverse-dip slope.