DETERMINATION OF SHEAR STRENGTH OF COHESIVE SOILS FROM SLIPPY SLOPES USING RING SHEAR TESTS

In all stability problems such as the bearing strength of the foundations, the stability of the slopes, the calculation of the lateral soil pressures on the retaining walls, it is necessary to compare the forces that cause the collapse along a possible collapse surface. Then, the forces that resist collapse should be calculated in order to evaluate a safety number against collapse. Ring shear tests should be utilized in order to get the shear strength parameters at high deformation levels for the cohesive soils that are a part of big slippy surfaces. In this study, 27 ring shear tests were performed on three different samples that have face slope stability problems in Turkey. The samples were subjected to different loading rates and the peak and residual strength parameters of the soils were obtained. The results were evaluated in change of the internal friction angles with the variation of the plasticity, fines content and the loading rates. Some relationships with high R2s between the parameters and the friction angle were observed from the test results.

Automated summary

In stability problems, comparing collapse-inducing forces along potential surfaces and calculating resistance forces is essential. Ring shear tests can provide shear strength parameters for cohesive soils on large slipping surfaces, with relationships observed between parameters and friction angle.