Study Of Marine Soft Soil Reinforcement And Its Dynamic Shear Modulus In Zhoushan Area

Zhoushan area is located in the east coast of Zhejiang Province,where there is a large amount of marine soft soil,which has adverse effects on the development of local marine resources and engineering construction.Deep stirring method is a common method for strengthening soft soil.Due to the unique marine geographical environment in Zhoushan area,it is necessary to consider the corrosion effect of seawater on marine structures,select suitable curing agent,and study the mechanical properties of solidified soil has important engineering value.In addition,the engineering construction in Zhoushan area is often subjected to the action of wave load and traffic load,so it is of great practical significance to study the dynamic characteristics of soil mass.In this thesis,sulphoaluminate cement with fast hardening,strong imperviability and resistance to seawater corrosion is used as curing agent to strengthen marine soft soil in Zhoushan area.The compression characteristics and vertical shear characteristics of solidified soil are studied experimentally.At the same time,the dynamic shear modulus of solidified soil under small strain is studied by Wille resonance column equipment in Germany.The main research results are as follows:1.Through the compression test,the experimental study on the compression characteristics of solidified soil under different sulphoaluminate cement content is conducted.It is found that cement content can significantly improve the compression characteristics of soil,and the compression amount,void ratio and compression coefficient decrease with the increase of cement content,while the compression modulus is the opposite.2.The direct shear test was carried out to study the direct shear properties of solidified soil.It was found that the content of sulphoaluminate cement was proportional to the growth of the cohesion of solidified soil,while the internal friction Angle gradually slowed down with the increase of the content of sulphoaluminate cement.3.Resonance column test was conducted to explore the effects of different effective confining pressures and sulphoaluminate cement content on the dynamic characteristics of solidified soil.It was found that the increase of cement content and effective confining pressure could improve the dynamic shear modulus of soil,and the increase of effective confining pressure on the maximum dynamic shear modulus of solidified soil was weaker than the effect of cement content.4.The Davidenkov model was used to fit the normalized dynamic shear modulus of sulphoaluminate cement solidified soil,and the relevant fitting parameters were given.The maximum dynamic shear modulus of the solidified soil was predicted by the double logarithm model,H-D model and Davidenkov model.