Paper contribution

Research on Deformation Characteristics and Instability Mechanism of Retrogressive Landslide Under the Coupling of Engineering Disturbance and Rainfall

Yanhong Zhu; Jiansong Shi; Chuanke Xu; Shengyun Huang; Yang Yu

Proceedings
EUROCK 2026
Pages
1525-1531
Submitted
22 April 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

Taking the landslide at section K2+550–K3+420 of a highway in North Macedonia as a case study, this paper systematically analyzes the deformation evolution and failure mechanism of a retrogressive landslide through integrated methods including surface crack investigation, surface and deep displacement monitoring, and MIDAS numerical simulation. The results indicate that typical arc-shaped tension cracks developed at the rear edge of the landslide. Monitoring data reveal that the main sliding direction ranges from 110° to 162°, with a maximum cumulative displacement of 310.2 mm. The deformation process exhibits a three-stage pattern characterized by "steady-rate deformation – accelerated deformation – accelerated creep." Deep displacement monitoring identified the slip surface at a depth of 38 m, located within the completely to strongly weathered phyllite layer. Numerical simulation results demonstrate that excavation unloading induced stress concentration at the slope toe. When superimposed with rainfall infiltration, the strength of the slip zone decreased, causing the factor of safety to drop from 1.16 to 1.04 and leading to the coalescence of the slip surface. The failure mechanism of the landslide can be summarized as: "Excavation unloading dominance → Local yielding → Rainfall infiltration softening → Progressive coalescence → Overall sliding." The findings provide a reference for the mechanism analysis and mitigation design of deep-seated retrogressive landslides.

Contributors

Authors

  1. Yanhong Zhu Sinohydro Bureau 7 Co.,Ltd.International Engineering Corporation, Chendu, China
  2. Jiansong Shi North China Engineering Investigation Institute Co.,Ltd., Shijiazhuang, Hebei, China; Technology Innovation Center for Groundwater Disaster Prevention and Control Engineering for Metal Mines,Ministry of Natural Resources, Shijiazhuang, China.
  3. Chuanke Xu Sinohydro Bureau 7 Co.,Ltd.International Engineering Corporation, Chendu, China
  4. Shengyun Huang North China Engineering Investigation Institute Co.,Ltd., Shijiazhuang, Hebei, China; Technology Innovation Center for Groundwater Disaster Prevention and Control Engineering for Metal Mines,Ministry of Natural Resources, Shijiazhuang, China.
  5. Yang Yu Sinohydro Bureau 7 Co.,Ltd.International Engineering Corporation, Chendu, China

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References

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