Optimization and Experimental Study of Penetration Depth of Pocket Penetrometer

Abstract

The pocket penetrometer has become an ideal tool for the rapid testing of soil parameters in the field due to its portability, ease of use, and cost effectiveness, but there is still room for improvement in its accuracy. In this study, a penetration test on red clay was investigated by increasing the penetration depth and combining the self-designed penetrometer, sample preparation method, and data analysis method. The improved sample preparation technique performs well in improving sample uniformity and preparation efficiency. The quantitative processing of the penetration curves improves the objectivity and accuracy of the test results. The penetration test results of various reshaped soils showed that the relationships between liquidity index, shear strength, and penetration resistance were less affected by the liquid–plastic interface. In addition, the penetration test results of remolded soils and in situ soils showed that the empirical formulas are still informative in evaluating the shear strength of soils despite the differences in the test soils.

Keywords

• pocket penetrometer
• red clay
• penetration test
• shear strength
• liquidity index