地震与同震冰滑坡综合作用下动水压力分布规律试验研究

摘要

A large number of landslides and collapses are often triggered by earthquake,but little attention has been paid to the risk assessment of glacier lake outburst under coaction of earthquake and ice avalanches.To investigate the characteristic of hydrodynamic pressures under coaction of earthquake and ice avalanches,experimental analysis of hydrodynamic pressures were conducted under separate earthquake action and ice avalanches action,respectively.The ice block sliding into the reservoir was added during the process of earthquake simulated by shaking table,the characteristic of combined hydrodynamic pressures caused by earthquake and ice avalanches were then observed.The results show that the seismic hydrodynamic pressures were decreased from the bottom to the top,which was in good agreement with Westergaard's briefly solutions.However the hydrodynamic pressures caused by ice avalanches were increased from the bottom to the top.Meanwhile the effect of the volume,the sliding block velocity and initial water depth were considered to study the characteristics of the hydrodynamic pressures,and an empirical equation was obtained to predict the maximum pressure loads acting on the dam.The hydrodynamic pressure distribution curves under coaction of earthquake and ice avalanches were approximately equal to the superposition of separate earthquake and ice avalanches actions,but the combined values were smaller than the superposition values,and the estimation method of maximum hydrodynamic pressure was proposed.%地震作用下常常引发大量的崩塌滑坡,但目前对冰湖溃决风险评估中,一直忽视了地震及同震触发滑坡的综合作用.为研究地震及同震触发滑坡二者综合作用下的动水压力分布规律,首先分别进行地震和冰滑坡作用下的动水压力试验分析,然后设计了在振动台模拟地震过程中加入冰滑坡入水的试验,观察地震与冰滑坡综合作用下动水压力的分布特点.结果表明:地震动水压力沿水深分布表现为上小下大的特点,其结果与Westergaard简要解吻合良好;冰滑坡作用下动水压力沿水深服从上大下小的分布规律,并分析了滑块体积、入水速度及初始水深等因素对最大动水压力值变化的影响,采用试验数据拟合得到冰滑坡入水动水压力值的经验公式;地震和冰滑坡共同作用时动水压力分布曲线近似于两者单独作用下动水压力幅值的叠加,只是综合值小于叠加值;提出地震与同震冰滑坡综合作用下最大动水压力的估算方法.