Measurement of Degree of Compaction of Fine-Grained Soil Subgrade Using Light Dynamic Penetrometer

Abstract

To determine the degree of compaction of subgrades filled with fine-grained soil, the compaction test and light dynamic penetrometer (LDP) test were carried out for low liquid-limit clay samples with different water contents in laboratory. Then, a prediction equation of the penetration ratio (PR) defined as the depth per drop of the hammer of LDP, degree of compaction (K), and water content (ω) was built. After that, the existing fine-grained soil subgrades on LDP-based field tests were excavated. The on-site PR values, water contents, and degrees of compaction of slopes were obtained. The estimated degrees of compaction using the prediction equation were compared with measured values of the degree of compaction in field. The results show that there is good consistency between them, and an error within 3.5% was obtained. In addition, the water content should be determined firstly while using the prediction equation which is proposed in this study. Therefore, a numerical method of the water content of a subgrade was developed, and the predicted and measured water contents were compared, which shows a relatively high relativity. Then, the degree of compaction of fine-grained soil subgrades can be calculated according to the predicting equation, which involves the penetration ratio (PR) and the numerically calculated water content as input instead of the measured value in the field.

Compaction Quality Control of Coarse-grained Soils Using Dynamic Penetration Test Results through Correlation with Relative Compaction Percentages

“…In order to use the DPT results and their relation with geotechnical properties of fine-grained soils, various studies have been conducted, especially in compaction quality control of the soils layers in road projects [20,21]. This is while that the majority of previous studies on DPT results and their relation with compaction control of coarse-grained soil layers, have been performed on physical models made in laboratory [22][23][24][25].…”

Laboratory and Field Evaluation of a-6 Lateritic Soil Treated With Reclaimed Asphalt Pavement and Ordinary Portland Cement

“…The use of Dynamic Cone Penetration test to indirectly evaluate the strength of subgrade, subbase and base courses have been a subject of study for more than two decades [22][23][24][25][26][27][28][29][30]. Dynamic cone penetration test has been used for the design of pavement structure [31,32], to check the degree of compaction during and after compaction [33,34] and to estimate the standard life of the pavement structure [35]. This method of evaluating the strength of in-situ compacted surfaces have been found to be simple, more accurate and more reproducible because of the difficulty in collecting an in-situ sample for California Bearing Ratio (CBR) test in the laboratory.…”