落石冲击对山区桥梁墩柱破坏的影响

为了研究落石冲击作用对山区桥梁墩柱破坏的影响规律，采用Holmquist—Johnson—Cook损伤本构模型构建了数值模型，并展开非线性显式动力分析，基于能量守恒原理检验了计算结果的数值稳定性。考虑了落石冲击高度、冲击速度、水平冲击角度和落石直径等影响因素，从体积损伤率和墩柱位移两个角度研究了各种因素对墩柱冲击破坏的影响。数值模拟结果和试验测试的加速度历程、破坏特征进行了对比，证明了数值模拟的合理性。研究结果表明，HJC本构模型能较好模拟钢筋混凝土墩柱在落石冲击作用下的破坏发展，在高能量冲击作用下，石块直径和冲击速度对墩柱破坏影响相对较大。

Influence on Damage of Bridge Pier in Mountain Area Under Impact Load of Rockfall

In order to investigate damage modes of the reinforced concrete bridge pier under impact load of rockfall in mountain area, numerical simulations were implemented based on Holmquist-Johnson-Cook (HJC) damage constitutive model. The energy conversation principle was used to testify numerical stability of the calculation results. A group of parameters, including impact height, impact velocity, elevation impact angle and the rock diameter, were taken into consideration to research their effect on damage degree of the bridge pier from points of view of failure volume rate and top displacement. By comparing with experimental results in acceleration history and failure characteristics, the simulation results were proved to be reasonable. The results indicated that failure development of the reinforced concrete bridge pier under impact load of rockfall could be simulated properly by HJC constitutive model. Furthermore, under high energy impact load, both rock diameter and impact velocity had a significant effect on damage degree.