Integrated Theory of Slope Deformation and Failure

ZHANG Ga, LUO Fang-yue

Journal of Changjiang River Scientific Research Institute ›› 2026, Vol. 43 ›› Issue (3) : 1-11.

PDF(3035 KB)
PDF(3035 KB)
Journal of Changjiang River Scientific Research Institute ›› 2026, Vol. 43 ›› Issue (3) : 1-11. DOI: 10.11988/ckyyb.20250992
Special Contribution

Integrated Theory of Slope Deformation and Failure

Author information +
History +

Abstract

[Objective] Slope failure theory is the fundamental basis for safety assessments of earth-rock dams, embankments, and slope engineering projects. Most existing slope analysis methods focus on single processes and struggle to adequately characterize slope deformation, failure characteristics, and their evolution under the coupling of multiple processes such as loading, moisture variation, and rheological effects. Moreover, conventional failure analyses often rely on stress-based failure criteria, limiting their ability to analyze the slope failure process and to reveal the underlying failure mechanisms. Commonly used engineering methods, such as the limit equilibrium method, have difficulty properly accounting for the coupling mechanism between slope deformation and failure, and their instability criteria often rely heavily on empirical judgment. Therefore, there is an urgent need to reveal the deformation-failure coupling mechanism of slopes under multi-process conditions and to establish a mechanical model for progressive slope failure. [Methods] This study proposed a novel research approach of “integrated analysis of the deformation and failure process”, which used measurable deformation to quantitatively track and describe the failure process, in combination with multi-factor testing and multi-perspective analysis. To this end, centrifugal model testing and measurement techniques for slope multi-processes were developed. These techniques could effectively simulate various loads, environmental changes, and engineering scenarios, while enabling full-field, whole-process measurement of slope deformation. Based on experimental observations, the slope failure process was quantitatively determined, and the progressive failure characteristics of slopes, along with the influence of loading conditions, were investigated. Under various test conditions, the deformation-failure coupling mechanism of slopes and its influencing factors were revealed, and the applicability of this mechanism was discussed. By introducing a coupled macro-micro integrated model for load-water-time effects and the slope deformation-failure coupling mechanism, three major mechanical equations were formulated, and an integrated analysis method for slope deformation and stability was developed. New equipment, independently developed on a centrifugal model testing platform, was used to simulate various loads, environmental changes, and engineering scenarios. A high-quality image-based displacement measurement system for the centrifugal field was developed, achieving multi-factor coupling simulation and measurable deformation. [Results] Slope failure was progressive and its evolution primarily depended on loading conditions. Changes in factors such as loading, water, and time induced localization near the potential failure surface of the slope, forming a “localization zone” that comprehensively reflected the main characteristics of slope deformation-failure behavior. The evolution of this localization zone reflected the coupling mechanism between the slope deformation localization process and the failure surface formation process. The increasing degree of localization development led to local failure within the zone, which subsequently exacerbated the degree of localization in the surrounding slope. The potential failure surface could represent this localization zone and exhibited a displacement coordination rule. Regardless of whether it was before, during, or after slope failure, the relative horizontal displacement of the soil masses on either side of the potential failure surface was independent of their spatial position. [Conclusion] Practical applications were conducted on typical projects including reservoir slopes and mining slopes. Slope displacement monitoring data obtained by the Global Navigation Satellite System were used for parameter inversion analysis, and the optimized parameters were then applied to calculate the slope response. The predicted slope displacement shows consistency with the monitored slope displacement, verifying the effectiveness of the proposed method. Furthermore, a practical slope failure case was analyzed using the proposed method. The slope stability safety factor was calculated. The results show that the slope stability gradually decreases and ultimately reaches a value lower than 1.0, which indicates that slope failure has occurred. Further analysis shows that the predicted failure time is in good agreement with the actual failure time. The findings demonstrate that the integrated deformation-stability analysis method can uniformly calculate slope deformation and stability. It effectively computes the entire process of slope deformation from small strains to post-failure, as well as the evolution of the stability safety factor. This method addresses the challenge of scientifically predicting slope stability based on deformation monitoring.

Key words

slope deformation / failure / stability analysis / centrifugal model test

Cite this article

Download Citations
ZHANG Ga , LUO Fang-yue. Integrated Theory of Slope Deformation and Failure[J]. Journal of Changjiang River Scientific Research Institute. 2026, 43(3): 1-11 https://doi.org/10.11988/ckyyb.20250992

References

[1]
TAYLOR D W. Fundamentals of Soil Mechanics[J]. Soil Science, 1948, 66(2): 161.
[2]
TERZAGHI K, RALPH B P. Soil Mechanics in Engineering Practice[M]. Hoboken: John Wiley & Sons, 1948.
[3]
沈珠江. 关于土力学发展前景的设想[J]. 岩土工程学报, 1994, 16(1): 110-111.
(SHEN Zhu-jiang. Perspectives on the Future Development of Soil Mechanics[J]. Chinese Journal of Geotechnical Engineering, 1994, 16(1): 110-111. (in Chinese))
[4]
黄润秋. 20世纪以来中国的大型滑坡及其发生机制[J]. 岩石力学与工程学报, 2007, 26(3): 433-454.
(HUANG Run-qiu. Large-scale Landslides and Their Sliding Mechanisms in China Since the 20th Century[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26(3): 433-454. (in Chinese))
[5]
曹光栩. 山区机场高填方工后沉降变形研究[D]. 北京: 清华大学, 2011.
(CAO Guang-xu. Study on Post-construction Settlement of High Fill Foundation in Mountainous Airport[D]. Beijing: Tsinghua University, 2011. (in Chinese))
[6]
迟世春, 周雄雄. 堆石料的湿化变形模型[J]. 岩土工程学报, 2017, 39(1): 48-55.
(CHI Shi-chun, ZHOU Xiong-xiong. Slaking Deformation Model for Rockfill Materials[J]. Chinese Journal of Geotechnical Engineering, 2017, 39(1): 48-55. (in Chinese))
[7]
姚仰平, 孔令明, 胡晶. 考虑时间效应的UH模型[J]. 中国科学:技术科学, 2013(3):298-314.
(YAO Yang-ping, KONG Ling-ming, HU Jing. Unified Hardening Model Considering Time Effect[J]. Scientia Sinica Technologica, 2013(3): 298-314. (in Chinese))
[8]
ALONSO E E, VAUNAT J, GENS A. Modelling the Mechanical Behaviour of Expansive Clays[J]. Engineering Geology, 1999, 54(1/2): 173-183.
[9]
JIAN W, XU Q, YANG H, et al. Mechanism and Failure Process of Qianjiangping Landslide in the Three Gorges Reservoir, China[J]. Environmental Earth Sciences, 2014, 72(8): 2999-3013.
[10]
ZHANG G A, QIAN J, WANG R, et al. Centrifuge Model Test Study of Rainfall-induced Deformation of Cohesive Soil Slopes[J]. Soils and Foundations, 2011, 51(2):297-305.
[11]
冯忠居, 王伟, 江冠, 等. 公路改扩建高边坡既有锚杆受力特性离心试验[J]. 长江科学院院报, 2024, 41(7):110-117.
Abstract
为研究改扩建边坡二次开挖下既有锚杆的受力特性及边坡稳定性,基于自主研发的模型试验锚杆角度支护装置,采用离心试验研究了锚固角度分别为10°、20°、30°、45°、60°及锚杆横向密度分别为1根/(18 cm)、1根/(12 cm)下顺层岩质高边坡开挖全过程中坡顶水平位移、锚杆轴力及坡内土压力变化规律。结果表明:相同锚固角度下,随着边坡开挖卸荷,坡顶累计水平位移非线性增加,且开挖坡顶增幅较开挖坡中大;锚杆轴力呈单峰分布,在开挖坡顶及坡脚时轴力增幅较大,轴力峰值靠近软弱面且随开挖卸荷先减小后增大,开挖后轴力峰值仍为开挖前的61%以上;随锚固角度的增加,坡顶水平位移先减小后增大,坡内土压力先增大后减小,即存在最佳锚固角度;建议边坡开挖宜采用分级开挖,并在开挖坡顶及坡脚时适当降低速率,综合考虑边坡坡度、岩层及软弱面倾角等因素,合理设计锚固角度。研究成果有助于工程技术人员在改扩建边坡二次开挖工程中选择合适的支护措施。
(FENG Zhong-ju, WANG Wei, JIANG Guan, et al. Centrifugal Test on Stress Characteristics of Existing Bolts in High Slope of Highway Reconstruction and Expansion[J]. Journal of Changjiang River Scientific Research Institute, 2024, 41(7):110-117. (in Chinese))
[12]
杨秀杰, 邓凯伦, 佘孟飞, 等. 分级加载下加筋边坡离心模型试验数值模拟[J]. 长江科学院院报, 2022, 39(2): 115-121.
Abstract
针对西南地区某机场加筋边坡的离心模型试验,建立与离心试验尺寸一致的有限元数值模型,并采用考虑时间因素的Cvisc蠕变模型与M-C模型,模拟分级加载过程中离心模型的位移、土压力、筋材拉力随时间的发展和分布情况,并与离心模型试验结果进行比较。采用Cvisc模型研究了不同筋材长度,以及不同部位的筋材加密和筋材模量增加对加筋边坡的影响。研究结果表明:Cvisc蠕变模型能较好地描述变加速度加载的离心模型试验,引进时间因子能反映出不同时刻下离心模型的位移、土压力、筋材拉力;随着筋材长度的增加,潜在滑面后移,边坡稳定性提高;在1/3坡高处筋材拉力和水平位移最大,通过对1/6~1/2坡高范围内筋材加密或模量增加,是提高边坡稳定性最有效的方法,筋材加密效果优于筋材模量增加。
(YANG Xiu-jie, DENG Kai-lun, SHE Meng-fei, et al. Numerical Simulation of Centrifugal Model Test of Reinforced Slope under Step Loading[J]. Journal of Changjiang River Scientific Research Institute, 2022, 39(2): 115-121. (in Chinese))
[13]
DUNCAN J M. State of the Art: Limit Equilibrium and Finite-element Analysis of Slopes[J]. Journal of Geotechnical Engineering, 1996, 122(7): 577-596.
[14]
ZHANG G, WANG L. Stability Analysis of Strain-softening Slope Reinforced with Stabilizing Piles[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2010, 136(11): 1578-1582.
[15]
SU Z, WANG G, WANG Y, et al. Numerical Simulation of Dynamic Catastrophe of Slope Instability in Three Gorges Reservoir Area Based on FEM and SPH Method[J]. Natural Hazards, 2022, 111(1): 709-724.
[16]
ZHANG K, CAO P, BAO R. Progressive Failure Analysis of Slope with Strain-softening Behaviour Based on Strength Reduction Method[J]. Journal of Zhejiang University SCIENCE A, 2013, 14(2): 101-109.
[17]
ZHANG G, WANG L. Integrated Analysis of a Coupled Mechanism for the Failure Processes of Pile-reinforced Slopes[J]. Acta Geotechnica, 2016, 11(4): 941-952.
[18]
LUO F, ZHANG G, MA C. Centrifuge Modeling of Drying-Wetting Cycle Effect on Soil Slopes[J]. International Journal of Geomechanics, 2023, 23(9): 04023157.
[19]
WANG L, ZHANG G. In-flight Simulation of Pile Installation in Slopes in Centrifuge Model Tests[J]. Geotechnical Testing Journal, 2015, 38(1): 50-60.
[20]
ZHANG G, HU Y, ZHANG J M. New Image Analysis-based Displacement-measurement System for Geotechnical Centrifuge Modeling Tests[J]. Measurement, 2009, 42(1):87-96.
[21]
ZHANG G, LIANG D, ZHANG J M. Image Analysis Measurement of Soil Particle Movement during a Soil-Structure Interface Test[J]. Computers and Geotechnics, 2006, 33(4/5): 248-259.
[22]
WANG L P, ZHANG G. Centrifuge Model Test Study on Pile Reinforcement Behavior of Cohesive Soil Slopes under Earthquake Conditions[J]. Landslides, 2014, 11(2):213-223.
[23]
WANG Y, ZHANG G, WANG A. Progressive Failure Behavior and Mechanism of Soil Slopes under Dynamic Loading Conditions[J]. International Journal of Geomechanics, 2017, 17(4): 04016102.
[24]
CHEN T, LUO F, ZHANG G, et al. Study on Deformation and Failure of Slopes under Coupled Application of Water Level Change and Vertical Load[J]. Bulletin of Engineering Geology and the Environment, 2021, 80(1):353-364.
[25]
LI M, ZHANG J M, LEE C F, et al. Centrifuge Model Tests on a Cohesive Soil Slope under Excavation Conditions[J]. Soils and Foundations, 2011, 51(5): 801-812.
[26]
ZHANG G, WANG R, QIAN J, et al. Effect Study of Cracks on Behavior of Soil Slope under Rainfall Conditions[J]. Soils and Foundations, 2012, 52(4): 634-643.
[27]
LUO F, ZHANG G, MA C. On the Soil Slope Failure Mechanism Considering the Mutual Effect of Bedrock and Drawdown[J]. International Journal of Geomechanics, 2021, 21(2): 04020247.
[28]
ZHANG G, WANG Y, LUO F. Simplified Method for Analyzing Soil Slope Deformation under Cyclic Loading[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2022, 14(6):1967-1976.
[29]
LUO F, ZHANG G. New Method for Full-process Deformation of Slopes Subject to Drying-wetting Cycles[J]. Bulletin of Engineering Geology and the Environment, 2025, 84(5): 239.
[30]
LUO F, ZHANG G, YAO Y. Macro-micro Tests of Cohesive Soil under Varied Normal and Shear Stresses Subjected to Drying-wetting Cycles[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2025, 17(9): 5893-5905.
PDF(3035 KB)

Accesses

Citation

Detail

Sections
Recommended

/