COMPARISON OF CBR VALUES OF DIFFERENT TYPES OF SOILS WITH VARYING ATTERBERG LIMITS

Abstract

CBR value is the predominant design parameter for flexible design. Generally, sub-grade strength is stated as California Bearing Ratio (CBR). Thicker layers are basically included in lower subgrade, while the powerful subgrade easily works with thinner pavement layers. In the saturation level subgrade is always depends on changes because of the water table’s subsidence, abrupt rise or flood, capillary action, and precipitation. Subgrade’s strength is changed due to changes in subgrade’s humidity levels. As well as it is very important that subgrade strength’s dependence’s exact nature on humidity variation must be clearly understood by the engineer. Improved design as well as maintenance practices are contributed if local soil CBR’s dependence on water content is understood clearly.
Usually, a well-established and easy method, CBR test, is utilized on samples of soil for measuring the subgrade strength. Although, subgrade strength can also be assessed through various other tests. The soil strength utilized for subgrade varies greatly depending on the soil’s saturation amount that means water amount which is exposed to the soil. Thus, in the current study, they attempted to vary the soaking degree as well as, therefore, the saturation level in different soil types as well as to evaluate the soil’s engineering properties that includes CBR, at various levels of saturation. It has been perceived that the worst engineering properties are discovered for coarse grained soils after 3 days of soaking as well as similar scenario was discovered for fine grained soils at the end of four days.