Research on the Evolution of Silt Embankment Stability Based on the Combined Effects of Compaction and Wet-dry Cycles
To investigate the long-term stability of embankment slopes subjected to the combined effects of compaction and wet-dry cycles,a study was conducted using a combination of laboratory triaxial tests and numerical simulations.The study focused on silt from a highway embankment section,where triaxial shear tests were performed under various wet-dry cycle frequencies and compaction levels.Shear strength parameters were obtained for different numbers of wet-dry cycles,which were then incorporated into a numerical simulation model for analysis.The effects of wet-dry cycles on potential slip surfaces were identified,and the evolution characteristics of the long-term stability of the silt embankment were explored.The results indicate that the strength of compacted silt decreases with the increase in wet-dry cycles.For instance,at a compaction degree of K=0.93,cohesion decreased by 24.1％、38.4％、44.1％and 51.0％,while the internal friction angle decreased by 11.4％、17.5％、21.9％and 25.4％after 2、4、6 and 8 wet-dry cycles,respectively.Notably,under different wet-dry cycle frequencies,potential slip surfaces were evident in the silt embankment slope,accompanied by numerous shear cracks in the slip body.While the initial safety factor of the embankment slope met the standard requirements,the stability significantly decreased due to wet-dry cycles.For K values of 0.96、0.93 and 0.90,the safety factor of the embankment decreased by 0.878、0.736 and 0.587,respectively,after 8 wet-dry cycles.This underscores the importance of providing sufficient safety reserves during embankment design,especially in regions prone to extreme climatic conditions.To enhance the long-term stability of silt embankments and increase resilience against degradation,emphasis should be placed on compaction quality and drainage.The findings of this study provide valuable insights for designing safety reserves in silt embankments.
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