Research On The Stress Deformation Characteristics Of Concrete-faced Rockfill Dams With Considering The Effect Of The Rockfill Rheology In The Lower Reservoir Of Xianyou Pumped Storage Power Station

With the vigorous development of water conservancy project,the height and the construction technology of CFRD have been constantly improved.Now,the CFRD has been used widely so that people have given more attention to the safety of dam.Then,the rheological effect of rockfill dam has attracted the attention of researchers in the continuous progress of dam monitoring technology.The rheological effect of rockfill can cause deformation of the dam in a long time,which will cause a certain influence on the critical seepage prevention parts such as panel and joint.What's worse,it may endanger the safe operation of the dam.A three-dimensional model of CFRD of Lower reservoir of Xianyou pumped storage power station is established to carry out the corresponding finite element calculation by using the conventional model of rockfill materials and the model of rockfill considering rheological effect.Finally,according to the calculation results,the influence of the rheological effect on the faced rockfill dam is analyzed.The main research contents are listed as follows:(1)The research progress of CFRD and the existing problems without considering the rheological properties of the rockfill have been expounded briefly.Then,the conventional models of rockfill are introduced in detail,meanwhile,the merits and demerits of the models are also pointed out and compared.In addition,the rheological mechanism of rockfill materials and the rheological model of rockfill are introduced.(2)The mathematical models adopted by the grid unit of faced rockfill dam are introduced detailly,and the three-dimensional calculation model of CFRD is built.Besides,the method of solving the integral equation of the nonlinear CFRD is described in detail.Then,the three-dimensional finite element calculation program of the CFRD is developed by using the FORTRAN language and the mid point increment method.(3)The stress and deformation of the CFRD of Lower reservoir of Xianyou pumped storage power station is analyzed through the simulation of dam material subarea,the simulation of the dam filling process and the Water storage process by using the step loading form,and the simulation of rockfill materials by using double yield surface model and the three-parameter rheological model of the Shen Zhu Jiang.(4)According to the calculation results of CFRD in the rheological effect and not included in the rheological effect,the influence of rheological behavior on the stress and deformation of the dam is analyzed.By comparing the calculated and measured values of the dam deformation and the slab joint displacement,the rheological effect of rockfill should be considered in the numerical analysis of the concrete faced rockfill dam.