Analysis And Research On Operation Monitoring Of Double Curvature Arch Dam Of Lijixia

The purpose of dam safety monitoring is to analyze the trend of the safe operation of the dam,through reasonable analysis of various important information of environment,working condition,hydrology,structure and so on in the dam area,combined with scientific theory and practical engineering experience,the whole operation condition of the dam is completely and accurately judged.In the actual operation process,through scientific analysis and accurate evaluation of the feedback information of the dam monitoring system,corresponding engineering measures can be taken to solve the problems in the safe operation of the dam in time.Therefore,the safety monitoring of the dam is very important in the management of water conservancy projects,which determines the safety of the whole project and the life and property safety of the downstream people.The current dam safety monitoring system is mainly divided into seepage,dam deformation and stress and strain monitoring,and seepage monitoring is a routine mandatory monitoring project.Based on the hyperbolic arch dam foundation uplift pressure of Lijiaxia hydropower station,on both sides of the long view of holes and measuring weir of groundwater study and qualitative analysis of monitoring data,based on which,we set up the sraristical model to analyse quantitatively how the water level,rainfall and aging factors effect on the dam foundation uplift pressure,seepage around the dam and dam foundation seepage flow.This text draws the following main conclusions as below:(1)The uplift pressure of dam foundation is mainly affected by the seepage pressure of upstream reservoir,but the change of pressure hole water level lags behind the change of reservoir water level;Temperature change and rainfall have some influence on the uplift pressure of dam foundation,but the influence is small;Except for the 6#and 7#sections,the change of the foundation uplift pressure of the other sections is normal,and no obvious abnormal signs have been found.(2)The seepage flow around the dam on both sides is similar.When a hole is close to the elevation on the same bank slope,the water level of the hole in front of the curtain is higher than that behind the curtain.In addition,the water level of the hole behind the curtain is lower than the water level of the hole in front of the curtain.The role of impervious curtain is more obvious.In addition to the phenomenon of water level increasing in some holes in the anti-seepage area,the water level of other holes is relatively stable.The seepage flow around the dam is normal.(3)The seepage amount of dam foundation is significantly affected by the change of reservoir water level,but the change of reservoir water level is small,which has little influence on the variation of seepage amount;rainfall also has a certain influence on the seepage of the dam foundation,which causes the increase of the groundwater level on the banks and slopes of the dam foundation;due to the influence of hillside groundwater,the groundwater on the right bank is higher than that on the left bank,and the total leakage of the corresponding measurement points of the same elevation on the right bank is generally larger than that on the left bank.If deducting the influence of human factors,such as water injection into the drainage pipe in the automation transformation,the leakage of each test section changes steadily on the whole,without obvious trend change.