Deformation Of Concrete Gravity Dam With Seepage Unusual Circumstances

Nowadays, water conservancy and hydropower project construction in the new stage of development, construction of the dam toward the direction of development of the high dam and some of the old dam had been built long also appeared many safety problems, making dam safety monitoring analysis work is more and more important.In this paper, on the basis of theoretical research combined with the actual operation of the dam site inspection,the monitoring data analysis and the analysis of the reference group of experts to assess. The organic combination of the four avoided many dam safety research only pay attention to the study of mathematical model and ignored its existing in the actual problem. This paper mainly studies the following problems:(1) First of all, analyzes and discusses the current external deformation monitoring in dam safety monitoring and dam foundation seepage monitoring the most commonly used monitoring instrument. And introduced its working principle, analyzed the advantages and disadvantages of all kinds of monitoring instrument, which could be according to the actual circumstances of the project to select the appropriate monitoring instrument.(2) The common abnormal phenomena existing in the external deformation monitoring and dam foundation seepage monitoring are analyzed and classified. It is easy to check the abnormal situation, so as not to draw a wrong conclusion. It is difficult to estimate the loss caused by the wrong conclusion. This paper presents the analysis of abnormal phenomena by the methods of physical origin, chemical element change and application data model analysis.(3) In the analysis of deformation anomaly, using the combination of the small probability data jump method and the adjacent monitoring point to identify the abnormal data points in the monitoring data. Effectively avoided due to lack of single point to judge the real abnormal value and lost good for dam safety analysis of real information, and realized by MATLAB program.(4) In dam safety monitoring data under the circumstances of less sample data using today’s superior performance in small sample regression prediction of partial least squares and support vector machine(SVM) regression forecast method, and compared the prediction accuracy of the two methods. The prediction results showed that the support vector machine used the grid search method to find the optimal regression parameters in small sample prediction accuracy was higher.(5) In the analysis of dam foundation seepage anomalies, the negative value of seepage pressure reduction coefficient was analyzed throng qualitative, quantitative, physical causes and the seepage pressure coefficient statistical model added seepage quantity. Using partial least squares regression analysis shows that the negative cause was mainly due to the concrete initial dam curtain grouting anti-seepage performance better, weak permeability of dam foundation rock and dam operation in a short period of dam foundation seepage has not yet reached a stable equilibrium state. In the analysis of the high water level of the dam foundation seepage, water injection experiments were carried out and the chemical elements in the water in the pressure tube and the chemical elements contained in the upstream water level and the downstream water level were also analyzed. According to the change of chemical element and the experiment of water injection, the cause of the high water level of the pressure measuring tube was determined.(6) The thesis gives a deformation and seepage of two hydropower stations abnormal situation as an example, the deformation and seepage of the abnormal situation represents some of the problems many hydropower stations in the dam safety inspection of the communist party of China, its analysis methods, ideas and the analysis results can be used as being similar to the power station of the question.