Study On Safety Risk Assessment Of Earth Rock Dam Seepage Based On Cloud Model And Fuzzy Analytic Hierarchy Process

The seepage of earth rock dam exists in the whole operation period,and whether it is normal or not is directly related to the safety of earth rockfill dam.When the external conditions of the earth rock dam change or the internal weakness,the earth rock dam will produce unsteady seepage and the seepage damage.If the development of the earth dam will cause the dam break and the safety of the earth rock dam,one or more methods are urgently needed to evaluate the safety of the percolation of the earth dam.Considering the applicability of cloud model and fuzzy analytic hierarchy process(fuzzy analytic hierarchy process)in dealing with the uncertainty of risk,this paper uses cloud model and fuzzy analytic hierarchy process to evaluate the safety risk of earth dam seepage.The main work and results are as follows:(1)From the mechanism of seepage failure,the main risk factors affecting the safety of earth rock dam seepage are analyzed.The influence rules of major risk factors are analyzed by the SEEP/W module of Geostudio software.The results show that the higher the water level in the upper reaches of the dam,the greater the risk of the seepage failure,the greater the permeability coefficient of the dam body,the greater the risk of the whole landslide in the downstream of the dam,the greater the permeability coefficient of the dam foundation,the local seepage failure of the earth rock dam.The greater the risk is,the less likely the landslide will happen.The larger the crest width and the slope rate,the smaller the risk of seepage failure.Integrating all risk factors,a safety risk assessment index system for earth rock dam seepage is established in general sense.The fuzzy analytic hierarchy process is applied to calculate the weight of evaluation index,and a fuzzy risk analysis model is established based on Fuzzy Analytic Hierarchy Process.(2)The reliability theory is used to calculate the risk probability of the seepage failure of earth rock dam,and the spatial variability of the permeability coefficient of the earth dam is taken into consideration in the calculation of the probability of seepage failure,and the probability estimation model of the seepage failure of earth rock dam based on random finite element is established.In addition,the dam failure consequences caused by seepage failure of earth rockfill dam are estimated from three aspects of life loss,economic loss and social environmental impact.Finally,according to thedefinition of risk,the safety risk of earth rock dam seepage is calculated,and the evaluation opinion is given according to the dam risk evaluation criteria.(3)The dimensionless method is used to unify the quantitative evaluation index and the qualitative evaluation index,the evaluation criterion of the seepage safety risk level of the earth rock dam is preliminarily given.According to the risk evaluation criterion,the evaluation indexes are assigned,and the seepage safety risk of the earth rock dam is determined by comparing the cloud map and calculating the similarity.Based on cloud model,a comprehensive risk assessment model for seepage safety of earth and rockfill dam is established.Based on the GUI function of Matlab software,a visual interface for risk assessment of seepage safety of earth and rockfill dam is developed based on cloud model and fuzzy analytic hierarchy process.(4)The risk identification model of earth rock dam seepage safety based on fuzzy analytic hierarchy process and the comprehensive evaluation model of seepage safety risk of earth rock dam based on cloud model are applied to the evaluation of the seepage safety risk of the dam in the sulphur gully reservoir,and the main risk factors are identified,and the soil is obtained through the comparison of cloud map and the similarity calculation.The rock dam seepage safety risk grade is "lower risk",which validates the practicability of the model.At the same time,the visualization interface of the seepage safety risk assessment of earth rock dam based on cloud model and fuzzy analytic hierarchy process is applied to the example,which can run normally and get the expected results,and the results are good.In addition,we compare the comprehensive evaluation model based on cloud model with the traditional fuzzy comprehensive evaluation method,and find that the evaluation model based on cloud model has more advantages.Finally,according to the evaluation results,several safety risk control measures for earth rock dam seepage are put forward.