Study On Deformation Behavior And Abnormal Symbols Of Concrete Dams With Particular Structures

In consideration of the particular structures of concrete dams and their influence on the deformation behavior of the dams,the mathematical and mechanical knowledge,such as gray system theory,fuzzy mathematics,viscoelastic plastic theory,together with the knowledge of dam engineering and structural analysis methods,are introduced into this dissertation,which performs relatively detailed study on the mathematical monitoring model of deformation,the inverse analysis of mechanical parameters of dam concrete and rock foundation,deformation procedure,abnormal symbols and the comprehensive appraisal methods of the deformation behavior of concrete dams with particular structures. The main points are as follows.1. Annual average of surveys and gray system model are used to set up the expression formula and model construction methods of time-effect,and determination method of 9 is illustrated,so as to get relatively reasonable time-effect exponent. Recursive regression method is applied for foundation of dynamic monitoring model. The mathematical model of deformation of the dams with joints or cracks is put forward,aiming at the nonlinear feature of such dams.2. In order to carry out the FEM computation,3-D isoparametric joint element of finite thickness is used to simulate the structural jionts such as longtitudinal slots,and lamella finite element is utilized to simulate seams in dam body and fractures in foudation. And nodes' stress obtained from FEM is optimized to improve their precision.3. Aiming at the shortcomings of the routine inverse analysis methods which only utilize the data of single-survey-point and single-direction,a new method is brought forward in which the deformation observation data of multiple-point and multiple-direction are made use of the inverse analysis. What's more,the displacement computed by FEM is optimized to better the inversion results by hydrid models.4. Meaningful probe is performed into the abnormal symbols of deformation of the dams with special structures. The curve of deformation against loads is lent to study the symbols,and monitoring models,time-effect exponent,catatrophic models are used to distinguish the abnormal symbols. Based upon the study of deformation procedure and its abnormal symbols, structrual analysis method is used to determine the deformation monitoring quota.5. The analysis methods of fuzzy classification and gray system classification are taken advantage of calssification of deformation behavior of the dams. And fuzzy comprehensive appraisal on dams' deformation behavior is performed.