In order to study the influence of nonlinearity to air cushion isolation effects of high arch dams,the gas-liquid-solid tri-phase coupling numerical model of the air cushion isolation control of high arch dams was presented,in which the material nonlinearity of air cushion was considered.The isolation effect simulation of Jinping high arch dam under Wenchuan seismic wave was carried out,and the results were compared to the ones neglecting the air cushion nonlinearity.It was showed that air cushion reduces the hydrodynamic pressure significantly.In normal and dead water level,the maximum of hydrodynamic pressure is reduced 70.2% and 75.3%, respectively with 1 m air cushion.Air cushion also causes a general reduction of tension stress and an improvement of stress distribution.Thereby,the anti-seismic capacity of the arch dam is improved significantly.Compared with the results neglecting the air cushion nonlinearity,the error of hydrodynamic pressure is less than 10%.Therefore,when the proportion of hydrodynamic pressure in total pressure is smaller,the material nonlinearity of air cushion can be ignored in air cushion isolation simulation of high arch dams.
