强震作用下南水北调双洎河渡槽结构非线性分析

渡槽作为一种常用输水建筑物，若处于地震高烈度区，抗震性能对其运行安全至关重要。为此，基于有限元分析软件ABAQUS开发了一种适用于大型双槽渡槽结构——南水北调双洎河渡槽工程的模拟钢筋混凝土材料非线性的纤维梁单元子程序，开展非线性地震响应分析，得到关键部位应力-应变曲线，以及跨中位移、速度、加速度、墩底弯矩、剪力时程曲线等。计算结果表明，强震作用下双槽渡槽非线性模型与线弹性模型地震响应差异较大，其中跨中位移、速度、加速度峰值非线性模型计算结果均有所增大；而墩底弯矩、剪力峰值有所减小；相同调幅下不同场地地震波的输入对结构响应峰值也有影响。所得结论为双槽渡槽结构的抗震设计计算提供了参考。

Nonlinear Analysis of Shuangjihe River Aqueduct Structure of South-to-North Water Diversion Project Under Strong Earthquake

The aqueduct, as a common water conveyance structure, is widely used in the South-to-North Water Diversion Project. The seismic performance of the aqueduct structure located in the high intensity area will seriously affect the safety of its operation. In this paper, based on the finite element analysis software ABAQUS, a fiber beam element subroutine was developed to simulate the nonlinearity of reinforced concrete materials for a large double-channel aqueduct structure. Taking Shuangjihe aqueduct of South-to-North Water Diversion Project as an engineering example, the nonlinear seismic response analysis was carried out, and the stress-strain curves of the key parts as well as mid-span displacement, velocity, acceleration, pier bottom bending moment and shear time history curve were obtained. The results show that the seismic response of the two-channel aqueduct nonlinear model is quite different from that of the linear elastic model under strong earthquake. The results of the nonlinear model of mid-span displacement, velocity and acceleration peak are all increased. However, the peak bending moment and shear force at the pier bottom are reduced. The input of seismic waves at different sites under the same amplitude modulation also has impact on the peak value of structural response. The conclusions will provide reference for seismic design and calculation of double aqueduct structure.