Correlations between CBR index, using the modified optimum proctor characteristics and lateritic soils identification parameters

The selection of soils for construction of engineering structures is done on the basic of set number of criteria. In road construction, the criteria used are the value of the CBR index at 4 days imbibition. For earth dams and road embankments where materials should be compacted at their maximum dry density, we will adopt the criterion: the compaction characteristics at its optimum modified proctor. The determination of these criteria are very time consuming and can generate several delays which is inconsistent with the strategies of productivity of Publics Works companies. To reduce these delays, relations permitting us to predict their values from soil identification parameters should be developed. In this context, 1500 laboratory test results obtained from samples collected throughout the Cameroon territory were studied. Correlations which obtained were tested on around thirty results gave a prediction with error lower than 6.02%.