某水电站边坡开挖爆破震动动力响应有限元分析

边坡爆破开挖的动力响应极其复杂,利用ANSYS进行模拟分析是有效可行的。详细介绍了某水电站高陡边坡计算模型的概化方法、建立方式。利用自编程序,将爆破震动实测速度时程曲线转化为加速度时程曲线作为计算荷载,对该边坡爆破开挖进行了ANSYS有限元模态分析和应力响应、位移响应、速度响应时程分析。模态分析结果表明,边坡的固有频率远低于爆破震动的主频,因此不会产生共振现象。时程分析结果表明,尽管此次爆破的震动速度最大值超标,各种应力在坡脚底部存在应力集中现象,但各应力值都较小,边坡没有发生任何塑性变形,若仅考虑爆破振动动力影响,不足以使边坡产生整体破坏;同时,随着爆破规模的增大,出现了明显的速度放大效应和惯性滞后效应。

Finite element analysis of dynamic response on blasting vibration in slope excavation of a hydroelectric power station

It was effective and feasible to utilize ANSYS software to imitated analysis although dynamic response to the slope blasting excavation was extremely complicated.Simple method and establishment way were introduced in detail of high steep slope computation model of a hydroelectric power station.Finite element of ANSYS,stress response,displacement response and speed response were analyzed this slope blasting excavation by utilizing the transformed accelerated time interval curve from the test speed time interval of blasting vibration as the calculating loads.The results of model analysis indicated that the resonance phenomenon would not occur because the slope inherent frequency is well lower than the main frequency of blasting vibration.The results of time interval analysis indicated that various kinds of stresses had stresses concentration phenomenon in slope bottom although the maximum speed of blasting vibrations exceeded the standard one,and any plastic shape did not create in slope although each stress was less,and it couldn't make the slope be destroyed wholly if we considered only the dynamic impact of blasting vibration.At the same time obvious speed magnifying effect and inertia hysteretic effect appeared with the increase of the blasting scale.