Estimation of California bearing ratio by statistical methods

California Bearing Ratio (CBR) is an important soil parameter for design of flexible pavements and runway of air fields. Use of CBR test results for design of roads, introduced in USA during ۲nd World War and subsequently adopted as a standard method of design in other parts of the world. CBR of soil may depends on many factors like maximum dry density (MDD), optimum moisture content (OMC), liquid limit (LL), plastic limit (PL), plasticity index (PI), type of soil etc. This study presents the application of different methods (Simple Linear Regression Analysis (SLRA) and Multiple Linear regression analysis (MLRA)) for the estimation of the CBR from sieve analysis, Atterberg limits, maximum dry density and optimum moisture content of the soils. Analysis of statistical indicators indicated high correlations (R۲=۰.۸۵–۰.۹۲, VAF=۸۵-۹۲%, RMSE=۱.۳-۲.۱%) between the sieve analysis, Atterberg limits (PL, LL, PI), maximum dry density (MDD) and optimum moisture content (OMC). It is recommended that the proposed correlations will be useful for a preliminary design of a project where there is a financial limitation and limited time.

کلیدواژه ها:

California Bearing Ratio ، Atterberg limits ، sieve analysis ، maximum dry density ، optimum moisture content