tailieunhanh - Báo cáo " Reconstructing sedimentary environments of MR1 core and investigating facies’ geotechnical properties through the piezocone penetration test in the Late Pleistocene-Holocene periods in the Mekong River Delta "

The aim of the study was to reconstruct sedimentary environments of the MR1 core and investigate geotechnical properties of sedimentary facies through the piezocone penetration test (CPTU). A core at the Vinhlong province, Mekong River Delta (MRD), sufficiently presented the Holocene facies of the area. Eight facies were identified based upon sedimentary properties. Characteristics of the units showed | VNU Journal of Science Earth Sciences 26 2010 19-31 Reconstructing sedimentary environments of MR1 core and investigating facies geotechnical properties through the piezocone penetration test in the Late Pleistocene-Holocene periods in the Mekong River Delta Truong Minh I loang1 Nguyen Van Lap2 Ta Thi Kim Oanh2 Takemura Jiro3 1Ho Chi Minh University of Science VNU Vietnamese Academy of Science and Technology HCMC Institute of Resources Geography Tokyo Institute of Technology Japan Received 14 September 2010 received in revised form 24 September 2010 Abstract. The aim of the study was to reconstruct sedimentary environments of the MR1 core and investigate geotechnical properties of sedimentary facies through the piezocone penetration test CPTU . A core at the Vinhlong province Mekong River Delta MRD sufficiently presented the Holocene facies of the area. Eight facies were identified based upon sedimentary properties. Characteristics of the units showed development of sedimentary facies. Each sedimentary facies was formed under different environment. Each sedimentary facies presents CPTU results differently. A facies has various sedimentary structures and materials such as the estuarine channel estuarine marine and delta front mouth bar facies values of cone resistance qt sleeve friction fs and pore water pressure u2 in its CPTU results will increase highly vary largely and present in saw-tooth shape in the overall plot of them as a function of depth. A facies sedimentary property is highly homogeneous such as the marsh bay and prodelta facies its values of qt fs and u2 increase almost linearly with depth. Keywords Vinhlong Late Pleistocene-Holocene MRD facies geotechnical properties CPTU. 1. Introduction The late Pleistocene-Holocene sediments in the MRD that has accumulated consist of several sedimentary facies each of which was formed in a different sedimentary environment and has typical sedimentary structures and materials and undergone complex changes 1 2 . The