Research On Safety Assessment Of Gravity Retaining Wall Based On The Set Pair Analysis-Combined Weighting Method

Gravity retaining wall is a commonly used slope retaining structure.In China,due to the rich stone materials,convenient local materials and simple construction methods,it has been widely used in the geotechnical engineering.However,after the gravity retaining wall is put into use for a certain number of years,under the influence of external environment and internal technical parameters changes,the retaining wall often produces various diseases,such as wall seepage,mortar loose,expansion joint stagger,wall roof platform cracking,etc.The occurrence of these diseases will lead to the retaining wall instability and damage,and even cause serious safety risks.At present,gravity retaining wall safety assessment has not been promulgated in China,and a set has not been established Accurate and perfect evaluation system.Therefore,this paper studies the safety assessment of gravity retaining wall.Referring to the existing research results of safety assessment in retaining structure or other fields,combined with the new safety assessment theory,this paper further studies the safety assessment method of gravity retaining wall.The main research results and conclusions are as follows:（1）According to the safety assessment steps of gravity retaining wall,four common causes of common diseases are analyzed.Four first level indicators and 24 second level indicators for safety assessment were identified.Build a gravity retaining wall safety evaluation index system based on qualified,qualified,unqualified and unqualified comments set.（2）Through the comparative analysis of the commonly used empowerment methods for the safety assessment of gravity retaining wall,the game theory combination empowerment method based on improved hierarchical analysis method and objective empowerment based on modified entropy weight method is proposed.In order to avoid the fuzzy resolution in the expert scoring process,matrix transmission inconsistency,unreasonable information entropy value and other problems.Game theory competicombines subjective and objective weights to obtain the optimal weight allocation.It calculates that the weights of the four first-level indicators are successively divided from large to small as:Force state index I₄,Appearance state index I₂,Natural environment state index I₁,and Internal state index I₃.（3）Introduce the common evaluation methods,and explain their respective advantages and disadvantages.The set-pair analysis theory is introduced into the set pair of certainty and non-certainty information in the evaluation,which obtains the same correlation between the actual value of each index and each level interval,and calculates the semi-partial subtraction set of each index to make the trend prediction on the macro level of the security index.Finally,the safety level is judged by the maximum membership and confidence criteria.The gravity retaining wall safety assessment model based on the set-pair analysis-combination empowerment method is established,with strong applicability and high reliability.Based on this model,a set of visual system for safety evaluation of gravity retaining wall is designed.（4）Combined with the specific engineering examples,use the established evaluation model to evaluate the safety situation of the actual retaining wall,determine its safety level,predict the development trend of its condition,and give treatment suggestions.The results prove the operability,reliability and accuracy of the model.