Rheological properties of dense natural cohesive sediments subject to shear loadings

• Published in: International journal of sediment research Vol. 29; no. 4; pp. 454 - 470
• Main Authors: YANG, Wen-yu, YU, Guo-liang, TAN, Soon keat, WANG, Hua-kun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2014; Ph.D. Candidate, State Key Laboratory of 0cean Engineering, School of Naval Architecture, 0cean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China%Prof. Dr., State Key Laboratory of 0cean Engineering, School of Naval Architecture, 0cean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China%Associate Prof., Maritime Research Centre, School of Civil and Environmental Engineering, Nanyang Technological University, Republic of Singapore
• Subjects: Brackish; Cohesive sediment; Rheology; Solid-liquid transition; Thixotropy; Yield stress; 凝聚力; 剪切应力; 剪切载荷; 天然; 屈服应力; 沉积物; 流变学行为; 流变性能; INW, China, People's Rep., Zhejiang Prov., Hangzhou Bay; China, People's Rep., Changjiang R; Thixotropy; Cohesive sediment; Solid-liquid transition; Rheology; Yield stress
• ISSN: 1001-6279
• DOI: 10.1016/S1001-6279(14)60059-7

Cohesive sediments exhibit complex rheological behaviors that are non-Newtonian and time-dependent when subjected to external loading. This paper presents the results of an investigation on the theological properties of three types of dense cohesive sediments, collected from the mouth of the Yangtze River, the shoal of the ttangzhou Bay, and the Yangcheng Lake in China. A set of rheological parameters （including viscosity, yield stress, etc.） was studied based on experiments that were conducted with a RheolabQC rheometer. Measurements of the flow curves, shear stress-time responses, and yield stresses were made. The solid-liquid transition of the dense cohesive sediments occurred both in the shear rate ramp tests and the shear stress ramp tests. This transition was not direct, but it was mediated by a transitional deformation regime or stress plateau. Both the Herschel-Bulkley model and Carreau model were able to describe the theological behavior of dense cohesive sediments, and the empirical expressions for calculating the parameters in these models were obtained by a dimensional and regression analysis. The yield stresses determined by the shear stress ramp test and by the vane method were compared and discussed. The influence of the water content on the rheological properties of dense cohesive sediments was considered.