tailieunhanh - Xác định vận tốc lắng đọng của trầm tích cố kết theo phương pháp đường cong bán thực nghiệm

Vận tốc lắng đọng trầm tích là tham số quan trọng tác động đến tính chất của quá trình vận chuyển trầm tích. Bài viết trình bày xác định vận tốc lắng đọng của trầm tích cố kết theo phương pháp đường cong bán thực nghiệm. | Vietnam Journal of Marine Science and Technology Vol. 21 No. 4 2021 481 491 DOI https 1859-3097 15164 https jmst Calculating the settling velocity of cohesive sediment based on semi- empirical method Le Nguyen Hoa Tien Vo Luong Hong Phuoc University of Science Vietnam National University- Ho Chi Minh city Vietnam E-mail lnhtien@ Received 26 December 2020 Accepted 24 June 2021 2021 Vietnam Academy of Science and Technology VAST Abstract Settling velocity is an important parameter affecting the characteristics of sediment transport. Especially for cohesive sediment in estuarine or mangrove areas determination of settling velocity is extremely complex. The study focuses on anlalyzing the relationship between settling velocity and sediment concentration. Based on the empirical formulas of Hwang 1989 and experimental data of Mehta and Li 2003 the settling velocity by concentration is considered with variation of four parameters a b m and n. The method is applied to calculate the settling velocity of cohesive sediment in Can Gio Biosphere Reserve Ho Chi Minh city. From collected sediment samples in fieldwork the settling column test is used to determine settling velocities. With 38 data of experimental settling velocity the semi-empirical curve is determined. The results show that the settling velocity in free settling is about 10-5 m s the maximum velocity is about 10-3 m s corresponding to the maximum concentration of kg m3. The resulting values of a b m and n are 3 and respectively. The results are reliable to real applications. Keywords Settling velocity cohesive sediment semi-empirical curve settling column test mangrove forests Can Gio. Citation Le Nguyen Hoa Tien Vo Luong Hong Phuoc 2021. Calculating the settling velocity of cohesive sediment based on semi-empirical method. Vietnam Journal of Marine Science and Technology 21 4 481 491. 481 Tạp chí Khoa học và Công nghệ Biển Tập 21 Số