Back-analysis For Material Of Concrete Face Rockfill Dam And Monitoring Model Research

Concrete face rockfill dam as a new type dam rockfill DAMS, because its on climate, geological landform has a strong applicability, in recent years about the design theory and construction of face rockfill dam is more and more experienced. But due to the pile of stone material anisotropy and its complexity, the laboratory test conditions and the scale effect and a series of factors, it is difficult to accurately test the material parameters of, also can’t correctly reflect the actual mechanical properties of the dam body. Therefore, according to the actual monitoring data of constitutive model parameters determined reasonable will has the vital significance. In addition, based on the real material parameters, can also be used for prediction and monitoring of dam operation to provide important basis.The detail contents:(1) At firs,introduces the constitutive model of concrete face rockfill dam and the finite element theory, expounds the soil reflect the nonlinear stress-strain relationship of Duncan-Chang constitutive relation model, and built Tianshengqiao-I concrete face rockfill dam3d finite element modeling.(2) Mathematical modeling method, combined with the traditional monitoring data of natural arch Tianshengqiao-I dam displacement data was analyzed. Including internal and external vertical displacement and horizontal displacement of dam body, on the one hand, through mapping the typical line displacement measuring point distribution of displacement and typical profile changes to analyze the displacement of the dam body, on the other hand to regression analysis, the typical measuring point measured displacements measured displacement of the regression model is established to quantitatively reflect the displacement of the dam body changes.(3) This thesis mainly discusses and investigates the constitutive model of concrete face rockfill dam material parameter back-analysis method and the theory combined with Tianshengqiao-I concrete face rockfill dam monitoring data, the parameters of the dam body of sensitivity analysis, choose high sensitivity parameters carry on back-analysis. Using genetic algorithm to optimize the BP neural network intelligent algorithm for the choice of material parameters for the back-analysis, get the real value of dam materials at run time, and by using the calculation of real value into the finite element model, calculate the displacement value of dam body under different water conditions and compared with the measured data, and validate the rationality of back-analysis and calculated value.(4) Based on the back-analysis and calculation on the basis of the displacement of the dam by finite element calculation changing under the true value of a variable component of the water pressure, and by using statistical methods to calculate time varying component and temperature varying component, so as to build the dam typical point of mixed monitoring model, to predict and monitor the running situation of the dam.