Characterization and Geotechnical Classification of Soils and Lateritic Gravelly Materials along the Songololo-Lufu Road Axis (Kongo Central Province, DR Congo)  

作　　者：Jean-Luc Albini Tshupa Blaise Mutombo Kabulu Ivon Ndala Tshiwisa Clément N’zau Umba-Di-Mbudi Jean-Luc Albini Tshupa;Blaise Mutombo Kabulu;Ivon Ndala Tshiwisa;Clément N’zau Umba-Di-Mbudi(Geo-Hydro-Energy Research Group, Geosciences Department, Faculty of Sciences and Technologies, University of Kinshasa, Kinshasa, Democratic Republic of Congo;Geosciences Department, Faculty of Sciences and Technologies, University of Kinshasa, Kinshasa, Democratic Republic of Congo;Geological and Mining Research Center (CRGM), Kinshasa, Democratic Republic of Congo;Polytechnic Faculty, President Joseph Kasa-Vubu University, Boma, Democratic Republic of Congo)

机构地区：[1]Geo-Hydro-Energy Research Group, Geosciences Department, Faculty of Sciences and Technologies, University of Kinshasa, Kinshasa, Democratic Republic of Congo [2]Geosciences Department, Faculty of Sciences and Technologies, University of Kinshasa, Kinshasa, Democratic Republic of Congo [3]Geological and Mining Research Center (CRGM), Kinshasa, Democratic Republic of Congo [4]Polytechnic Faculty, President Joseph Kasa-Vubu University, Boma, Democratic Republic of Congo

出　　处：《Journal of Geoscience and Environment Protection》2024年第5期355-372,共18页地球科学和环境保护期刊（英文）

摘　　要：This study aims to characterize from a geotechnical point of view, the soils as well as the lateritic gravels along the Songololo-Lufu road route in the Kongo Central Province in the Democratic Republic of Congo (DRC). Ten soil samples and eight lateritic gravel samples were analysed and tested in the laboratory. For each sample, identification parameters were determined such as particle size analysis, natural water content, Atterberg limits (plasticity index and consistency index), but also compaction and lift parameters such as optimal water content, maximum dry density and CBR lift index. All materials and soils have been classified according to the Congolese Road Standard (NRC) and according to the American HRB classification. The test results show us that clay soils almost always contain between 70% and 90% fine fraction;the grained fraction represents less than 30% in clay samples. For lateritic gravels soils, the percentage of fine elements varies between 35% and 15%;in sand around 20%;the gravelly fraction represents a little more than 50% of the soil. The majority of soil facies encountered define a plasticity index lower than 15. As for the consistency index, we obtained values greater than 1, both for clayey soils and for gravelly soils. The classification according to NRC defined for these soils the types Ae1 and Ae2 for the clayey facies and the types GL1 and GL2 for the gravelly soils, while that of the HRB identified the classes and subclasses A-6 and A-7-6 for clayey soils, and subclass A-2-6 for gravelly soils. The optimal water content values obtained range between 10.2% and 23.10%;the maximum dry densities are between 1.66 and 2.07 t/m³ and the CBR index is between 6 and 26. As for the lateritic gravels materials of the Songololo region, the percentage of fine elements generally remains between 12% and 31%;the plasticity index is between 8 and 18;the optimal dry density is around 2 t/m³;the optimal water content is between 9.8% and 14.5% and the CBR index is between 27 andThis study aims to characterize from a geotechnical point of view, the soils as well as the lateritic gravels along the Songololo-Lufu road route in the Kongo Central Province in the Democratic Republic of Congo (DRC). Ten soil samples and eight lateritic gravel samples were analysed and tested in the laboratory. For each sample, identification parameters were determined such as particle size analysis, natural water content, Atterberg limits (plasticity index and consistency index), but also compaction and lift parameters such as optimal water content, maximum dry density and CBR lift index. All materials and soils have been classified according to the Congolese Road Standard (NRC) and according to the American HRB classification. The test results show us that clay soils almost always contain between 70% and 90% fine fraction;the grained fraction represents less than 30% in clay samples. For lateritic gravels soils, the percentage of fine elements varies between 35% and 15%;in sand around 20%;the gravelly fraction represents a little more than 50% of the soil. The majority of soil facies encountered define a plasticity index lower than 15. As for the consistency index, we obtained values greater than 1, both for clayey soils and for gravelly soils. The classification according to NRC defined for these soils the types Ae1 and Ae2 for the clayey facies and the types GL1 and GL2 for the gravelly soils, while that of the HRB identified the classes and subclasses A-6 and A-7-6 for clayey soils, and subclass A-2-6 for gravelly soils. The optimal water content values obtained range between 10.2% and 23.10%;the maximum dry densities are between 1.66 and 2.07 t/m³ and the CBR index is between 6 and 26. As for the lateritic gravels materials of the Songololo region, the percentage of fine elements generally remains between 12% and 31%;the plasticity index is between 8 and 18;the optimal dry density is around 2 t/m³;the optimal water content is between 9.8% and 14.5% and the CBR index is between 27 and

关 键 词：Songololo-Lufu Lateritic Gravels CLASSIFICATION GEOTECHNICAL NRC 

分 类 号：F42[经济管理—产业经济]