Shear Strength Study of Cohesive Sediment in The Lower Yellow River

It is a complex problem for the cementation strength between cohesive fine sediment. In this study, the cementation strength of cohesive fine sand is studied, and the cementation strength index is expressed by shear strength in soil mechanics. Through the shear strength test of remolded cohesive fine sediment, the shear strength parameters of cohesive fine sediment were obtained, and the effects of water content and particle size distribution on the shear strength of cohesive fine sediment were analyzed. The results show that the cohesion of cohesive fine sediment decreases with the increase of water content, the internal friction angle varies with the change of water content due to different particle size distribution, and the shear strength decreases with the change of water content. For cohesive fine sediment with median size less than 0.03mm, the shear strength with water content ranging from 5% to 30% ranges from 100 kPa to 600 kPa. For fine sediment with median size less than 0.01mm, the shear strength with water content ranging from 30% to 52% decreases significantly, mostly within 100 kPa. It can be seen that the water content has a great influence on the shear strength of cohesive fine sand. This study provides a basis for understanding the cementation strength of cohesive fine sediment grains and lays a foundation for further study on the scour resistance of cohesive fine sediment.