Study On Properties Of Dredged Soil At High Water Content Solidified Soil With Soda Residue

Dredged silt generally has the characteristics of high moisture content and low strength,so it needs to be treated by solidification technology,and the reaction between the solidifying agent and the water and soil particles in the silt can be used to reduce the moisture content and improve the strength,so as to achieve the purpose of facilitating transportation,landfill and conversion into good geotechnical materials.The traditional curing agent is mainly cement.In order to improve the high curing cost caused by the high moisture content of dredged silt,industrial waste residue is often added as an auxiliary curing agent.Soda residue is a solid waste produced by soda ash production,which is mostly disposed by means of surface storage,and has some environmental problems such as soil salinization and groundwater pollution.In this paper,the unconfined compressive strength and durability of the solidified dredged soil under the condition of dry and wet circulation were studied,taking soda residue,ground granulated blast furnace slag and other alkali activators as solidified agent.Combined with the microscopic test,the hydration reaction mechanism of solidification was revealed.The study will provide the theoretical support for the solidification technology of dredged soil at high water content using soda residue.The main research contents are:(1)Basic mechanical properties of solidified dredged soil with soda residue,ground granulated blast furnace slag,nd sodium silicate.Direct shear tests and unconfined compressive strength tests were carried out to study the influence of initial moisture content,dosage of curing agent and curing age on the strength of solidified soil.Then the solidification plan that meets the general requirements of engineering filling materials was determined.(2)Basic mechanical properties of solidified dredged soil with soda residue,ground granulated blast furnace slag,and carbide slag.Based on the orthogonal test scheme,the unconfined compression tests were carried out to study the influence of the dosage of curing agent and curing age on the strength of solidified soil.The solidification effects of sodium silicate and carbide slag on dredged soil were compared.(3)Mechanical properties of solidified dredged soil with soda residue,ground granulated blast furnace slag,and carbide slag under dry and wet cycling conditions.The curing agent ratio satisfying the soil filling performance requirements was selected.Unconfined compressive tests were carried out to study the influence of the number of dry and wet cycles and the dosage of curing agent on the strength properties of solidified dredged soil.The durability of solidified soil under dry-wet cycling conditions was discussed.(4)Microscopic mechanism analysis.The microstructure(SEM)observation and mineral composition(XRD)analysis of the solidified soil were carried out.The influences of factors such as the dosage of curing agent,curing age and times of dry and wet cycles on the microstructure and composition of the solidified soil were studied.