Study on Formation Mechanism and Treatment Scheme of Consequent Bedding Landslide at K35+240～+620 Section of Wanda Expressway

DOI: https://doi.org/10.62517/jcte.202606207

Author(s)

Haitao Li1, Lingwei Kong2

Affiliation(s)

1Jilin Tiedao University, Jilin, China; 2China Railway Northwest Research Institute Co., Ltd., Lanzhou, China

Abstract

Aimed at the consequent bedding rockslide at K35+240–+620 section of Kaijiang–Kaizhou section of Chongqing Wanda Expressway, this paper systematically analyzes the engineering geological conditions, deformation characteristics and failure mechanism of the landslide through field investigation, drilling exploration and mechanical calculation. The stability of the landslide under natural and rainstorm conditions is evaluated, and two control schemes are put forward and compared. The results show that the landslide is a typical rainstorm-induced consequent bedding rockslide controlled by the interface of sandstone and mudstone, with a total volume of about 1.064×10⁶ m³. The upper hard sandstone and lower soft mudstone structure, groundwater enrichment at the lithologic interface, and high cutting excavation and blasting disturbance are the main inducing factors. The stability coefficient is 1.05–1.11 under natural condition and 1.00–1.06 under rainstorm condition, which is in an unstable state. Scheme One (anti-slide piles + anchor cable ground beam + intercepting and drainage system) is recommended, with a total investment of about 18.1866 million yuan. The scheme has the advantages of high safety, good durability and reliable long-term performance, which can effectively ensure the operational safety of the expressway. The research results can provide reference for the investigation, design and treatment of similar consequent bedding rockslides in eastern Sichuan.

Keywords

Consequent Bedding Landslide; Geological Characteristics; Failure Mechanism; Anti-Slide Pile; Anchor Cable; Drainage System

References

[1] Li X, Zhao L H. Deformation mechanism and stability control of consequent bedding rockslides in expressway cutting slopes[J]. Chinese Journal of Rock Mechanics and Engineering, 2020, 39(S2): 3356-3366. [2] Wang F, Zhang J M. Analysis on failure mode and treatment technology of consequent bedding landslide in Three Gorges Reservoir area[J]. Journal of Engineering Geology, 2019, 27(3): 589-597. [3] Liu Y, Wei C F. Application of combined support system of anti-slide pile and anchor cable in large-scale landslide treatment[J]. Rock and Soil Mechanics, 2021, 42(S1): 399-408. [4] Zhou W, Zhang Y B. Key technologies for investigation and design of extra-thick consequent bedding rockslide[J]. Bulletin of Soil and Water Conservation, 2022, 42(2): 156-163. [5] Hu P, Kong L W. Study on rapid treatment technology of expressway landslide under operating conditions[J]. Railway Investigation and Surveying, 2023, 49(2): 41-46. [6] Chen J L. Design and application of drainage system in consequent bedding landslide treatment[J]. Highway, 2021, 66(5): 123-128. [7] China Railway Northwest Research Institute Co., Ltd. Code for Design of Landslide Prevention Engineering[M]. Beijing: China Railway Publishing House, 2019.