Laboratory Geotechnical Investigations on Five Silty Soils Sampled along the Banks of the Lubumbashi River/Haut-Katanga/DR Congo

• Published in: International journal of engineering research in Africa (Print) Vol. 65; pp. 73 - 89
• Main Authors: François, Bertrand, Mukoko, Gustave, Kiyukeno, Yannick
• Format: Journal Article Web Resource
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.01.2023
• Subjects: Alluvial clays; Alluvial deposits; Alluvial soil; Alluvial soils; Civil engineering; Clay soils; Compression tests; Compression zone; Compressive strength; Direct shear test; Engineering (all); Engineering, computing & technology; General Earth and Planetary Sciences; General Environmental Science; Geotechnical; Geotechnical investigations; Identification test; Ingénierie civile; Ingénierie, informatique & technologie; Internal friction; Oedometric compression test; Parameter identification; Plasticity index; Plasticity indices; River banks; Shear strength; Shear tests; Silty soils; Soil compressibility; Soil investigations; Soil properties; Soil strength; Soil structure; Tri-axial compression tests; Triaxial compression test; Triaxial compression tests; Waterways; Congo-Democratic Republic of Congo; Triaxial Compression Test; Oedometric Compression Test; Alluvial Soils; Identification Test; Direct Shear Test
• ISSN: 1663-3571; 1663-4144; 1663-4144
• DOI: 10.4028/p-3hLFCa

An adequate design of port structures along waterways requires a good knowledge of the geotechnical properties of the surrounding soils. This study aims to characterize the geotechnical laboratory properties of alluvial soils along the Lubumbashi river (section between the Tshombe and Tshondo bridges, approximately 3 km long) in the city of Lubumbashi, province of Haut Katanga in DR Congo. To meet this objective, five sampling zones were selected from which samples were taken with a hand auger and various geotechnical laboratory tests were performed. Identification tests reveal that the tested soils have low to moderate plasticity and are in the range of sandy silt to silty sand with a low fraction of clay particles, essentially inactive. Oedometric compression tests reveal that the soils in place are (moderately) compressible. The consolidated undrained (CU) triaxial compression and direct shear tests indicate effective values of internal friction angle and negligible drained cohesion that, are consistent for this kind of soil. In the end, the compressibility and strength parameters of the five tested soils are correlated with their plasticity index, showing a decrease in the shear strength and an increase in the compressibility when the plasticity index increase.