Evaluation Of The Safety State Of Lining Structure During The Operation Period Of The Water Diversion Tunnel In Northwest China

Diversion tunnels,as an important part of the water delivery system building,play an irreplaceable role in the diversion project.In the diversion tunnels built in the northwestern region of China,due to the long-term water transport operation and the influence of adverse climatic and geological conditions,a series of disease problems appeared in the tunnel structure,which affected the water transport operation to a certain extent.Based on field investigation,literature research,norm collection,and expert consultation,this paper analyzes the various disease factors that affect the safety of the lining structure of the diversion tunnel,and establishes an evaluation index system for the safety status of the lining structure during the operation period of the diversion tunnel in the northwest region.The classification of indicators has established a safety evaluation model of the lining structure during the operation period of the diversion tunnel in the Northwest China.The in-service diversion tunnel Pandaoling Tunnel was used as a case for evaluation and research.The collected engineering testing data was used as the support,theoretical analysis was the guide,model calculation was used as the basis,and the result review was used as a means to reasonably evaluate the diversion tunnel.According to the evaluation results of the lining structure's safety status,determine whether to repair or strengthen it to ensure the safety of the diversion tunnel.This thesis focuses on evaluating the safety status of the lining structure of the diversion tunnel during the operation period in the northwestern region.It involves the identification and analysis of the lining structure disease factors of the diversion tunnel,the establishment of the safety indicator evaluation system for the lining structure of the diversion tunnel,and the lining structure of the diversion tunnel.Classification of safety status,determination criteria of secondary evaluation indicators,comprehensive evaluation model of safety status of lining structure of diversion tunnel.The main research contents and results of this article are:(1)Research on classification of safety status of lining structures during the operation period of diversion tunnels in Northwest China.With reference to the safety status classification methods of other hydraulic buildings and existing railway and highway tunnels,this paper uses a clearer and simpler four-level classification method to classify the safety status of the lining structure of the diversion tunnel.(2)Study on the evaluation index system of the safety status of the lining structure during the operation period of the diversion tunnel in Northwest China.Analyze the problems and the occurrence mechanism of the lining structure of the diversion tunnel during operation in the northwestern region,determine the influential factors for evaluating the safety status of the lining structure of the diversion tunnel,and construct an evaluation index system for thesafety status of the lining structure during the operation of the diversion tunnel.The standard lists the specific judgment criteria for each secondary evaluation index.(3)Study on the evaluation model of the lining structure safety status during the operation period of the diversion tunnel in Northwest China.Due to the non-linear relationship between the evaluation indicators,through the applicability analysis of the evaluation model,a Real-coded Accelerating Genetic Algorithm(RAGA)based on real number coding was established to optimize the optimal projection direction of the Projection Pursuit(PP)model.A comparative analysis model of the evaluation results of the safety state of the lining structure of the diversion tunnel during operation and of the Probabilistic Neural Networks(PNN).(4)Case study of typical in-service diversion tunnels in Northwest China.The statistics of the damage of the Pandaoling Tunnel of the diversion tunnel were analyzed,and the causes of the disease were analyzed,and the problems of the lining structure affecting the safe operation of the diversion tunnel were summarized.RAGA-PP model was evaluated.According to the evaluation results,the safety status of the lining structure of the two tunnel sections 76 + 235 ~ 76 + 988,91 + 765 ~ 91 + 958 is Class A safety,76 + 988 ~ 77 + 833,79+ 097 ~ 79 + 435,79+ 475 ~ 79 + 779,79 + 779 ~ 85 + 091,85 + 113 ~ 90 + 070,91 + 500 ~91 + 765 are class B basic safety,77 + 833 ~ 79 + 097,79 + 435 ~ 79 + 475,85 + 091 ~ 85 +113,90 + 070 ~ 91 + 500 are Class C unsafe.On this basis,the PNN model is used to make a comparative analysis of the evaluation results.According to the test results,it can be seen that the evaluation results of the safety status of the lining structure of the last 6 tunnel sections obtained by PNN are consistent with the RAGA-PP model evaluation conclusions.Further verification the reliability of the evaluation results obtained.