Study On Stabilized Formula Of Lacustrine Soft Soil In Hefei And Mechanical Properties Of Stabilized Soil

There are a lot of soft soil in some inland cities and some coastal cities,soft soil has a high natural water content,large void ratio,high compressibility,low shear strength,low bearing capacity and poor permeability and other physical and mechanical characteristics.In such a region,the construction of the project often brings adverse effects,the most important problem is that the settlement of the foundation is large and uneven,it is necessary to take proper measures to deal with the problem so as to carry out the construction of the project.In the current practical projects,put cement as based soft soil curing agent is often used,but there are serious consumption of resources and environmental pollution in the process of cement production.As a kind of industrial waste residue,ground granulated blastfurnace slag can be used for reinforcement of soft soil.It can not only solve the problem of piling up and pollution of slag,but also reduce the consumption of resources.This paper takes Hefei lacustrine soft soil as the research object,and uses ground granulated blastfurnace slag instead of cement to reinforce Hefei Lacustrine soft soil.Because of the ground granulated blastfurnace slag has a potential hydration activity,therefore the selection of calcium oxide and sodium sulfate as the activator on the hydration of ground granulated blastfurnace slag were used to stimulate the curing of soft soil,the mixture ratio between three kinds of additives was optimized by Box-Behnken method,and study the physical and mechanical properties of stabilized soil.The main contents and conclusions are as follows:(1)When ground granulated blastfurnace slag,calcium oxide and sodium sulfate are added to the lacustrine soft soil in Hefei separately for stabilizing,so as to determine the range of them.(2)Through the analysis of the interaction between three kinds of additives,found: when the curing time was 7 days,the interaction between GGBS and calcium oxide and the interaction between GGBS and sodium sulfate improved the strength of stabilized soil significantly;when the curing time was 28 days,the interaction between GGBS and calcium oxide improved the strength of stabilized soil obviously.(3)Based on Box-Behnken method,using Design-Expert software to analyze the mixing ratio between three kinds of additives,get optimal mixing ratio: groundgranulated blastfurnace slag is 11.97%,calcium oxide is 4.21%,and sodium sulfate is4.65%.(4)According to the analysis of moisture content of the stabilized soil under the optimum mixing ratio and the stress?strain curve of ground granulated blastfurnace slag stabilized soil and cement stabilized soil,the result shows that the hydration reaction of the stabilized soil is more thorough,the moisture content of the stabilized soil is lower,and ground granulated blastfurnace slag stabilized soil and cement stabilized soil?s initial tangential modulus is low,the stabilized soil stress reach the peak,the sample will be damage,but there are still some residual strength.(5)Through the unconfined compressive strength test,analyze the influence of the amount of organic matter on the strength of stabilized soil.It is concluded that the influence of the amount of organic matter on the strength of the stabilized soil under the optimum mixing ratio has obvious regularity.