Effect of vertical confinement on soaked CBR of clay

Abstract

The upper subgrade of many countries, especially Lebanon, is manly formed from a clayey soil. This kind of soil presents a weak CBR value when it is soaked. Scientists around the world always try to find a way to solve this problem, because it causes big troubles such as cracks and holes on highways. The normal CBR test is done by a continuous load. The main purpose of this project is to study the effect of vertical confinement on soaked CBR of soil. Five CBR tests are performed to each of ten different soils. Each test with different ring loading. The first with no rings loading, the second with one ring loading, the third with two rings loading, the fourth with three rings loading, and the last with four rings loadings. These results are linked to the soil properties using the identification test. The analysis shows that vertical confinement has a positive effect on the soaked CBR of clayey soils. The CBR value increases as the number of ring loadings increase.