Analysis Of Seepage Behavior Of A Rockfill Concrete Gravity Da

With the continuous innovation and development of mass concrete technology,in recent years,rock-fill concrete dam construction technology has been widely used due to its unique advantages,and has broad development prospects in the field of hydraulic engineering.However,rock-fill concrete dam construction technology is a new type of mass concrete technology,and the theoretical research on seepage is relatively lacking,and the seepage safety problem still needs to be solved.The analysis of the seepage behavior of rock-fill concrete dam is conducive to a comprehensive understanding of the impact of seepage.Adverse effects of rock-fill concrete dam.For this reason,this paper will conduct an in-depth analysis of the seepage behavior of a rock-fill concrete gravity dam in an actual project from three aspects:inversion of permeability coefficient,numerical simulation of seepage field,and seepage safety evaluation.The main research contents and conclusions are as follows:（1）The reasons for the differences in the permeability coefficients of rock-fill concrete materials obtained through different tests were analyzed,and the seepage characteristics of rock-fill concrete dams were summarized;Bayesian stochastic inversion theory and AM-MCMC Based on the sampling algorithm,the response surface model is introduced instead of the seepage finite element model,and the entropy-blind number theory is introduced to analyze the uncertainty of the permeability coefficient,and a method for inversion of the permeability coefficient of rock-fill concrete dam based on the AM-MCMC sampling algorithm is proposed.（2）In view of the insufficient analysis of the seepage field of existing rock-fill concrete dams and the difficulty of simulating the drainage hole curtain,a finite element analysis method and calculation program for seepage of rock-fill concrete dam were established,and"replacing well rows with fractures"was adopted The drainage hole curtain was simulated by using the method,and the seepage finite element model of the dam body（including dam body,anti-seepage body,corridor and cushion）and dam foundation（including dam foundation rock mass,anti-seepage curtain and drainage hole）was established,and the It performs numerical simulation of the seepage field.（3）Aiming at the insufficiency of using field observation data for seepage safety evaluation indicators of rock-fill concrete dam,a combination of monitoring and numerical simulation is used to analyze from multiple levels and indicators,and a rock-fill concrete dam is established.Concrete dam seepage safety comprehensive evaluation index system,introduces AHP-EWM to comprehensively assign the weight of each index,introduces cloud model theory to realize the transformation from quantitative index value to qualitative concept description;finally gives the heap model based on AHP-EWM and cloud model Comprehensive evaluation process for seepage safety of stone concrete dams.（4）The seepage behavior of a rock-fill concrete gravity dam in an actual project is comprehensively analyzed.The AM-MCMC sampling algorithm proposed in this paper is used to realize the inversion of the permeability coefficient of the project,and the inversion value of the permeability coefficient of the C₉₀15 rock-fill concrete inside the dam body,the C₉₀15 self-compacting concrete anti-seepage body on the upstream surface and the rock mass of the dam foundation are obtained.And the uncertainty analysis of the obtained inversion value is carried out.The seepage field of the rock-fill concrete gravity dam is simulated by using the finite element method,and the key seepage indicators such as the head distribution,hydraulic gradient,uplift pressure and seepage volume in the seepage field of the dam body and the dam foundation are analyzed.Using the comprehensive evaluation method for seepage safety of rock-fill concrete dam based on AHP-EWM and cloud model,the seepage safety of the dam section where the corridor in the rock-fill concrete gravity dam is located is comprehensively evaluated.The results show that:in the rock-fill concrete gravity dam The seepage safety of the dam section where the entire corridor is located is in a safe state.