Study on the characteristics of ccu and φcu obtained from undisturbed samples of large-scale embankments and the stability analysis with ccu and φcu
2025 Volume 20 Issue 2 Pages 215-234
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2025 Volume 20 Issue 2 Pages 215-234
In practical stability analysis, ccu and φcu obtained from CU triaxial tests are used as constants that define the failure criterion. However, ccu and φcu are actually constants that determine the undrained shear strength at any consolidation pressure. In this study, the characteristics of ccu and φcu obtained from the envelope of the Mohr’s circle of total stress were studied from the results of triaxial CU tests using undisturbed samples conducted for the safety investigation of large-scale embankments, and the engineering meanings of ccu and φcu were examined. Further, based on the clarified engineering meanings of ccu and φcu, a new formula was proposed to calculate the safety factor of embankments using ccu, φcu, and the internal friction angle φu of the UU triaxial test under undrained conditions. As a result of comparing the safety factors calculated by the current formula, which calculates ccu and φcu as the strength constants of the failure criterion, and the proposed formula under various conditions, it was found that the current method was almost consistent with the proposed formula when φcu was around 15˚, but the safety factor was underestimated when φcu was greater than 15˚ and overestimated when φcu was less than 14˚.
