【摘要】 目前一般采用振动台试验、离心振动台试验和有限元动力分析来获得土石坝在设计地震荷载作用下的形态和抗震性能。本文结合孔宪京等的土石坝振动台试验结果开展了颗粒流细观数值模拟研究,克服了传统连续介质力学的宏观连续性假设,形象而直观地表现出坝体在动力荷载作用下的破坏特征。数值模拟规律与振动台试验规律基本一致。同时还分析了坝体颗粒粘结强度和地震峰值加速度变化对坝体破坏特征的影响。数值结果表明,当颗粒间粘结强度较低时,表现为坝体表面颗粒的滑动破坏,粘结强度稍大时,会出现局部的小块颗粒团整体滑动破坏;随着峰值加速度的增大,坝顶沉降量在增大,坝体破坏特征不变。更多还原

【Abstract】 The shape and seismic behavior of earth rock-fill dam under designed seismic load are usually simulated by shaking table test,shake table for the centrifuge test and finite element dynamic analysis.Mesomechanical simulation was analyzed based on the shaking table test in Reference[1],which overcomes the deficiency of macro-continuity assumption in continuum mechanics and can demonstrate the failure characteristics of dam under dynamic loading intuitively and vividly.The law obtained from numerical simulation is almost consistent with the one obtained from the shaking table test.Besides,the influencing factors of bond strength of particle and peak acceleration of seismic wave on the characteristics of damage in the dam were analyzed.The simulation results indicate that the failure characteristics of dam are particle sliding on the dam surface with very low bond strength and particle cluster sliding on the dam surface with slightly higher bond strength.With the increase of peak acceleration,the settlement of dam crest is becoming larger,but the failure characteristics of dam remains unchanged.更多还原