Large-Scale Test Model of the Progressive Deformation and Failure of Cracked Soil Slopes

Abstract

A large-scale test bed (LWH=6 m×3 m×2.8 m) instrumented with various sensors is used to examine the effects of rainfall infiltration and evaporation on the deformation and failure of cracked soil slopes, taking the Anhui area along the Yangtze River as a field example. The results indicate that (1) during rainfall, the soil around the shallow shrinkage fissures attains transient saturation, and the attendant decrease of matric suction is the primary cause of the shallow slope failure; (2) slope deformation continues during post-rainfall evaporation; (3) if a period of evaporation is followed by heavy rainfall, soil creep is concentrated near the deepest cracks, and two zones of steep gradients in pore pressure form at the crest and toe of the slope. Finally, a saturated zone forms near each crack base and gradually enlarges, eventually forming a continuous saturated layer that induces the slope instability or failure.

Keywords

slope failure / geological engineering / cracked soil slope / large-scale test / progressive deformation

References

[1] Aleotti P. A Warning System for Rainfall-Induced Shallow Failures. Engineering Geology, 2004, 73(3/4): 247-265.

[2] Cao L, Zhang H, Chen Y. Hydraulic Properties Analysis of the Unsaturated Cracked Soil. Journal of Shanghai Jiaotong University (Science), 2017, 22(1): 35-44.

[3] Chen T L, Zhou C, Wang G L, . Centrifuge Model Test on Unsaturated Expansive Soil Slopes with Cyclic Wetting-Drying and Inundation at the Slope Toe. International Journal of Civil Engineering, 2018, 16(10): 1341-1360.

[4] Dong S C, Samsonov S, Yin H W, . Two-Dimensional Ground Deformation Monitoring in Shanghai Based on SBAS and MSBAS InSAR Methods. Journal of Earth Science, 2018, 29(4): 960-968.

[5] Fan Q Y, Liu J Q, Yang D S, . Model Test Study of Expansive Rock Slope under Different Types of Precipitation. Rock and Soil Mechanics, 2016, 37(12): 3401-3409. (in Chinese with English Abstract)

[6] Greve A, Andersen M S, Acworth R I. Investigations of Soil Cracking and Preferential Flow in a Weighing Lysimeter Filled with Cracking Clay Soil. Journal of Hydrology, 2010, 393(1/2): 105-113.

[7] Huang C C, Ju Y J, Hwu L, . Internal Soil Moisture and Piezometric Responses to Rainfall-Induced Shallow Slope Failures. Journal of Hydrology, 2009, 370(1/2/3/4): 39-51

[8] Hudacsek P, Bransby M F, Hallett P D, . Centrifuge Modelling of Climatic Effects on Clay Embankments. Proceedings of the Institution of Civil Engineers-Engineering Sustainability, 2009, 162(2): 91-100.

[9] Iqbal J, Dai F C, Hong M, . Failure Mechanism and Stability Analysis of an Active Landslide in the Xiangjiaba Reservoir Area, Southwest China. Journal of Earth Science, 2018, 29(3): 646-661.

[10] Jia G W, Zhan T L T, Chen Y M, . Performance of a Large-Scale Slope Model Subjected to Rising and Lowering Water Levels. Engineering Geology, 2009, 106(1/2): 92-103.

[11] Kim M S, Onda Y, Uchida T, . Effect of Seepage on Shallow Landslides in Consideration of Changes in Topography: Case Study Including an Experimental Sandy Slope with Artificial Rainfall. CATENA, 2018, 161: 50-62.

[12] Li L Q, Ju N P, Guo Y X. Effectiveness of Fiber Bragg Grating Monitoring in the Centrifugal Model Test of Soil Slope under Rainfall Conditions. Journal of Mountain Science, 2017, 14(5): 936-947.

[13] Li Z, He Y J, Li H E, . Model Test on Slope Landslides under Antecedent Rainfall. Journal of Hohai University (Natural Sciences), 2016, 44(5): 400-405. (in Chinese with English Abstract)

[14] Lim T T, Rahardjo H, Chang M F, . Effect of Rainfall on Matric Suction in a Residual Soil Slopes. Canadian Geotechnical Journal, 1996, 33(2): 618-628.

[15] Lourenço S D N, Sassa K, Fukuoka H. Failure Process and Hydrologic Response of a Two Layer Physical Model: Implications for Rainfall-Induced Landslides. Geomorphology, 2006, 73(1/2): 115-130.

[16] Lu P, Wu H B, Qiao G, . Model Test Study on Monitoring Dynamic Process of Slope Failure through Spatial Sensor Network. Environmental Earth Sciences, 2015, 74(4): 3315-3332.

[17] Pan Y H, Chen J P, Wu L Q, . Evolution Mechanism and Rainfall Warning Criteria for Maijianwo Slope in Henan Province, China. Geotechnical and Geological Engineering, 2017, 35(1): 183-194.

[18] Römkens M J M, Prasad S N. Rain Infiltration into Swelling/Shrinking/Cracking Soils. Agricultural Water Management, 2006, 86(1/2): 196-205.

[19] Schilirò L, Montrasio L, Mugnozza G S. Prediction of Shallow Landslide Occurrence: Validation of a Physically-Based Approach through a Real Case Study. Science of the Total Environment, 2016, 569/570: 134-144.

[20] Seboong O, Lu N. Slope Stability Analysis under Unsaturated Conditions: Case Studies of Rainfall-Induced Failure of Cut Slopes. Engineering Geology, 2015, 184: 96-103.

[21] Sun H Y, Zhong J, Zhao Y, . The Influence of Localized Slumping on Groundwater Seepage and Slope Stability. Journal of Earth Science, 2013, 24(1): 104-110.

[22] Tsai T L, Chiang S J. Modeling of Layered Infinite Slope Failure Triggered by Rainfall. Environmental Earth Sciences, 2013, 68(5): 1429-1434.

[23] Tsai T L, Yang J C. Modeling of Rainfall-Triggered Shallow Landslide. Environmental Geology, 2006, 50(4): 525-534.

[24] Wang R, Zhang G, Zhang J M. Centrifuge Modelling of Clay Slope with Montmorillonite Weak Layer under Rainfall Conditions. Applied Clay Science, 2010, 50(3): 386-394.

[25] Wu L Z, Huang R Q, Xu Q, . Analysis of Physical Testing of Rainfall-Induced Soil Slope Failures. Environmental Earth Sciences, 2015, 73(12): 8519-8531.

[26] Wu L Z, Zhang L M, Zhou Y, . Theoretical Analysis and Model Test for Rainfall-Induced Shallow Landslides in the Red-Bed Area of Sichuan. Bulletin of Engineering Geology and the Environment, 2018, 77(4): 1343-1353.

[27] Zeng L, Liu J, Shi Z N. Effect of Colluvial Soil Slope Fracture’s Anisotropy Characteristics on Rainwater Infiltration Process. Journal of Traffic and Transportation Engineering, 2018, 18(4): 34-43. (in Chinese with English Abstract)

[28] Zhang G, Wang R, Qian J Y, . Effect Study of Cracks on Behavior of Soil Slope under Rainfall Conditions. Soils and Foundations, 2012, 52(4): 634-643.

[29] Zhang M, Yin Y P, Huang B L. Mechanisms of Rainfall-Induced Landslides in Gently Inclined Red Beds in the Eastern Sichuan Basin, SW China. Landslides, 2015, 12(5): 973-983.

[30] Zhang Y Z, Wang L J, Liu S H, . Model Test on the Performance of the Expansive Soil Slope During Wetting-Drying Cycles. Journal of Zhengzhou University (Engineering Science), 2015, 36(6): 114-118. (in Chinese with English Abstract)

[31] Zheng J L, Zhang R, Yang H P. Highway Subgrade Construction in Expansive Soil Areas. Journal of Materials in Civil Engineering, 2009, 21(4): 154-162.