Prediction of Compaction Behaviour of Soils at Different Energy Levels

Abstract

Compaction tests forms one of the important aspects in geotechnical engineering practice. These tests are time consuming and require large quantity of soil also. In this paper based on the results of the compaction tests carried out for different soils of varying plasticity characteristics at different compaction energies and on published data, it has been brought that there is a good correlation between the optimum moisture content and plastic limit for the . In addition to this one can predict the modified compaction parameters just knowing the plastic limit of the soil. For the present investigation, three different soils from North Cyprus (Tuzla, Degirmenlik and Akdeniz) and a soil from Turkey (highly plastic montmorillonitic clay) were chosen. These soils are heavily in use for civil engineering activities like construction of pavements, embankments and earth retaining structures. Compaction tests were carried out at three different energy levels for the four soils described.. They are standard Proctor test (SP), reduced modified Proctor (RMP) and modified Proctor (MP). For the standard Proctor, the compaction energy works out to be 593.7 kJ/m 3 . In the modified Proctor test, the compaction energy works out to be 2693.3 kJ/m 3 . In the reduced modified Proctor test the procedure is same as modified Proctor except the number of layers are three instead of five. The compaction energy works out to be 1616 kJ/m 3 . [1] Based on the experimental results obtained for maximum dry density vs. optimum moisture content for the four different soils with different compaction energy levels it has been found that irrespective of soil type and compaction energy levels both the maximum dry density and optimum moisture content are linearly related with a very high correlation coefficient of R= 0.994. Results obtained from laboratory tests as well as from literature show that the correlation between maximum dry density and OMC for different soils, compacted for two compaction energy levels is very good. It is thus seen that one can predict OMC knowing the plastic limit with reasonable accuracy. Having obtained OMC one can get the maximum dry density from equation(1) obtained in this study. From experimental results it has been found that both OMC and maximum dry density of Proctor’s test results and that of modified Proctor’s test results of authors’ as well as data collected from literature correlate very well. It is seen that the correlation is highly satisfactory. Having obtained both OMC and maximum dry density for Proctor’s energy level one can get the OMC and maximum dry density for modified Proctor condition also.