Research On The Mechanism Of Seismic Wave Input About High Rockfill Dam

With the construction of high rockfill dam,it is necessary to study and improve the method of the seismic response analysis.Because the traditional model with rigid boundary can't consider the influence of radiation damping of infinite foundation and travelling wave effect on the dynamic response and stabilization of the rockfill dam,a more reasonable method of seismic response analysis was realized in this paper through the introduction of viscous-spring artificial boundary and relevant seismic wave input method.Firstly,the particular derivation of viscous-spring artificial condition was introduced based on the different forms of scattering wave,and an amendment tothe boundary parameters was raised after the research in point fountain questions.Secondly,the generic and special expressions of equivalent load were derived in detail, and the physical meanings was discussed profoundly.And then the expressions of equivalent load were derived in the condition that two dimensional and three dimensional homogeneous linear elastic field under the incidence of P/SV/SH wave at a certain angle,and subsequently the program designed to realize this course was validated by a scattering question of semicircular valley.Finally,the method was applied to the seismic response analysis of a two dimensional homogeneous rockfill dam under the vertical and oblique incidence of seismic wave.And this paper successionally discussed the simulation precision of displacement and acceleration in the free field under the incidence of seismic wave,the influence of scattering fountain position on the calculation accuracy in the model with viscous-spring boundary,dam and foundation dynamic interaction reprensented by the model,and the influence of the seismic wave type and travelling wave effect on the acceleration distribution of the rockfill damIt was shown that it is feasible to apply this method to the seismic response analysis of the rockfill dam.Moreover the results could be used for the reference of the rockfill dam seismic design and the basis for the further research of complex travelling wave effect influence on the three dimensional three hundreds metres high rockfill dam.