Evaluation of strength coefficients of sandy levee soils under various triaxial test conditions

Abstract

Soil parameters, e.g., strength coefficients c andφ are very important factors for stability inspections of river levees against seepage failure. However, large differences have been found among the φ cu obtained by CU triaxial tests, the φ' obtained by CU-bar triaxial tests, and the φ d obtained by CD triaxial tests. In the present paper, a series of CU-bar and CD triaxial tests for various soil materials is carried out in order to confirm the difference in strength coefficients obtained under different triaxial test conditions. The test results suggest that CU tests are susceptible to the variation in samples and that it is difficult to consider the ccu and φ cu of natural soils with these tests. On the other hand, CD and CU-bar triaxial tests are not influenced by the variations in samples, and therefore, easy to confirm the strength coefficients.