Study On Operation Period Health Assessment Of Lining Of Highway Tunnel In Water Rich Stratum

In the whole life of a highway tunnel,due to the joint action of external factors such as hydrogeology,climate conditions and internal factors such as design defects and construction defects,a series of diseases will be occurred in the lining structure.Those diseases not only affect the safety of tunnel construction,but also reduce the safety of lining structure during operation.Among them,highway tunnels in water rich strata are especially affected by those diseases because of the worse geological conditions.Therefore,to ensure the lining structure of highway tunnel in water rich stratum can be in normal service during the operation period,it is necessary to understand its health status during the operation period and make a reasonable evaluation.Based on this,this paper uses literature research,questionnaire survey,empirical analysis,theoretical analysis and other means to study the structural health evaluation of highway tunnel lining structure in water rich stratum during operation period.The main results are as follows:(1)On the premise of elaborating the main influencing factors of the health state of the lining structure of the highway tunnel in the water rich stratum during the operation period,the lining structure diseases are defined as the structural health evaluation indexes of the lining structure of the highway tunnel in the water rich stratum during the operation period.According to the literature research,the main diseases and their characteristics which have a great impact on the health of lining structure during operation period are preliminarily selected.Then,the reliability and validity of the selected diseases are analyzed by questionnaire survey and empirical analysis method.Finally,the comprehensive evaluation index system of lining structural health of highway tunnel in water rich stratum during operation period is established.(2)By literature analysis,the health status of highway tunnel lining structure in water rich stratum during operation period is divided into four grades.On this basis,to make the comprehensive evaluation index associated with the health grade of lining structure in operation period,the paper gives the four level classification standard of each secondary index through literature research method.(3)The comprehensive evaluation index system is divided into three levels,and according to the qualitative and quantitative characteristics of each level,the weight of each evaluation index is allocated by using AHP and entropy weight method.In the process of weight calculation,the scaling method of AHP is simplified to make it more suitable for lining structure health evaluation in operation period.(4)The GRA-Fuzzy evaluation model used to evaluate the health operation period of highway tunnel in water rich strata is established based on Grey Relation Analysis and fuzzy comprehensive evaluation.And the method of establishing the grey fuzzy comprehensive matrix is modified in the process of establishment of GRA-Fuzzy evaluation model.An appropriate engineering case is selected to verify the evaluation model’s practicability and accuracy.