Comparison And Selection Of Soft Foundation Treatment Schemes Based On Muilt-attribute Decision Theory

The soft soil has poor mechanical properties and strong instability,which often leads to uneven settlement of the roadbed and even the instability and collapse of the embankment.There are many ways to deal with soft soil foundations,each with its own advantages and disadvantages and limitations.There are also many factors affecting soft foundation treatment.How to choose a reasonable foundation treatment is directly related to project quality,project schedule and engineering investment.Therefore,it is preferable to judge the soft-based treatment scheme based on the mathematical model in a clear and clear way.In view of this,based on the grey relational degree and fuzzy analytic hierarchy process,this paper attempts to establish a comprehensive evaluation model of soft foundation processing scheme based on grey-fuzzy analytic hierarchy process,and combines the airport avenue and Changji high-speed exit node overpass project for soft foundation treatment.The optimization of the scheme proves the reliability of the model.The main research contents of this paper are as follows:(1)According to the characteristics and influencing factors of the soft foundation treatment method,based on the analytic hierarchy process and the principles established by the evaluation index system,the evaluation index system of the soft foundation treatment scheme with technical feasibility,economic rationality and environmental impact as the evaluation content is constructed.(2)When engineering designers use F-AHP to judge soft-base processing schemes,the determination of membership degree is often a complicated task.In view of this,this paper will make some improvements to F-AHP,that is,the gray system theory is introduced into the fuzzy analytic hierarchy process,and Establish a grey-fuzzy hierarchical comprehensive evaluation model.The main idea of the model is to combine the degree of relevance in the grey system theory with the membership degree in fuzzy mathematics,and quantify some gray,boundary fuzzy and difficult to quantify factors in the soft base processing evaluation system.Then,according to the weight,the soft base processing schemes are comprehensively evaluated.(3)Taking the airport bridge and Changji high-speed exit node overpass project as the research object,the gray-fuzzy hierarchical comprehensive evaluation model is used to analyze the example.And it is proved that the grey-fuzzy hierarchical comprehensive analysis method can provide technically reliable and economically reasonabledecision-making for soft-based processing schemes.