Study On The Application Of Nickel Slag In The Foundation Treatment Of Coastal Soft Soil

With the continuous development of China's economy and the iron and steel industry,the demend of nickel is increasing.However,more and more nickel slag was generated in the process of smelting of nickel as the same time.Because of the less ways of disposal of nickel slag and the lower comprehensive utilization ratio,massive land resource was occupied by the nickel slag which was piled on the open-air field.Based on the above situation,this paper relies on the method of vacuum preloading to explore the treatment efficiency of nickel slag used in the soft soil by the way of replacing the medium-sized sand and coarse sand with nickel slag as the drainage channel of the method.This study hopes to get the good treatment efficiency of the soft soil and deal with the nickel slag effectively at the same time,and improve the comprehensive utilization ratio of nickel slag finally.At first the properties of the nickel slag were studied by a series of tests and compared with the sand,the result of tests and contrast indicated that the difference of properties between nickel slag and coarse sand was little,and the nickel slag has specific advantage which the coarse and doesn't,and the indicators of material of drainage channel for the engineering was satisfied.It is feasible to treat soft soil foundation with nickel slag instead of the medium-sized sand and coarse sand.Secondly,the reinforcement mechanism of vacuum preloading was analyzed in detail in this paper.By collecting and sorting out the examples of the treatment of soft soil foundation in Lianyungang coastal area and comparing various methods,the method of vacuum preloading was proved to have better advantage.Based on the measurement data,the changing rules in the vacuum preloading process of vacuum degree,surface settlement,pore water pressure,layered settlement and deep horizontal displacement were deeply researched.The physical and mechanical indexes of soft soil,vane shearing strength and ground bearing capacity were compared before and after the consolidation.The result showed that the strength of soil layer has been greatly improved after the treatment of nickel slag,and it can meet the requirement of engineering design.It is viable to teat the soft soil foundation with nickel slag.Finally,according to the measurement data,several methods were used to predict the final settlements of the soil layer of the reinforcement area.By comparing and analyzing the calculation results,exponential curve method was proved to have better applicability in Lianyungang coastal area;and the software of ABAQUS was alwaysused to simulate the settlements of the reinforced area,the results showed that the analog values and measured values had same trends and high accuracy,and it could be used to verify and predict in the practical projects.