Evaluation Of Expansive Soil Expansion And Shrinkage Grade Based On Cloud Model And Intuitionistic Fuzzy Set

Expansive soil or improved expansive soil has expansion and shrinkage,and different treatment and disposal methods are often adopted in engineering according to the expansion and shrinkage grade of expansive soil or improved expansive soil,so it is necessary to evaluate the expansion and shrinkage grade of expansive soil or improved expansive soil.Because the improved expansive soil of coal gangue is widely studied,the evaluation method of expansive grade of improved expansive soil of coal gangue is discussed in this paper.However,there are three shortcomings in the traditional evaluation methods:①the number of indicators and the reliability of indicators;②the traditional multi-index evaluation method can not overcome the problem of the randomness of the index,that is,the measured value of the evaluation index can not meet a certain grade standard at the same time,which makes it difficult to distinguish;③the model of the boundary cannot be realized.Paste processing,that is to say,the measured value of evaluation index is often caused by observation,calculation error or trade-off error,which may lead to different classification of indexes near the grade boundary.It is necessary to put forward an accurate and scientific method to solve the above problems.Cloud theory and intuitionistic fuzzy set theory,which have prominent advantages in uncertainty classification and boundary fuzzy processing,can solve these problems well.In this paper,according to the factors that affect the expansion and shrinkage of expansive soil or coal gangue,and according to the classification method of expansion and shrinkage grade at home and abroad,the index of rating is selected and the classification standard is established.In this paper,it is considered that a single evaluation model may lead to errors in judgment.Therefore,based on entropy method and cloud theory,the entropy weight-cloud model and entropy weight-intuitionistic fuzzy set model are established respectively.Then taking the coal gangue improved expansive soil as an example,the model is established and the concrete evaluation grade is obtained through the verification of the measured value of the test index.Finally,compared with the traditional method,the conclusion is as follows:(1)According to the deficiency of the evaluation index of expansive soil expansion and shrinkage in the past,five indexes,liquid limit,plastic index,maximum linear shrinkage rate,maximum volume shrinkage rate and free expansion rate,were selected,and the classification standard was established.(2)In this paper,the entropy weight-cloud model with the core value of synthetic certainty U(μ(x)ωi)and the entropy weight-intuitionistic fuzzy set model with score Mj(Un)as the core value are established.(3)The model is illustrated by the test samples of 0%、3%、6%、9%coal gangue content,and the feasibility and validity of the model are verified by comparing it with the Ke zunjing method and the expansion potential method.At the same time,the swelling and shrinkage characteristics of expansive soil can be effectively reduced by adding 6%or more coal gangue.