基于流固耦合的南水北调渠道结构动力破坏机理研究

以南水北调中线渠道工程为研究对象,建立了水体-结构-地基耦联体系的渠道模型,运用Fluid 30单元实现水工结构流固耦合计算,计算了地震工况下的渠道结构的破坏情况。计算结果与Westergaad传统方法进行对比,验证了Fluid 30单元方法的正确性。研究结果表明,Fluid 30单元耦合方法计算的结构频率均值较传统方法增加10.93%,渠道结构进行地震分析时,水体的流固耦合效应不容忽视;渠道衬砌板分缝处为最薄弱部位,且出现了应力集中,每个纵缝处下表面均出现了较大的拉应力;衬砌结构在地震中可视为做整体移动,衬砌上表面比下表面所受的压应力更大,而在接近分缝处这一情况恰好相反。

Study on Dynamic Failure Mechanism of Channel Structure of South-to-North Water Transfer Based on Fluid-Structure Interaction

Taking the channel project of the Middle Route of South-to-North Water Diversion Project as research object,a water-structure-foundation coupling model is established,and the damage of channel structure under seismic condition is calculated by using Fluid 30 element method to achieve the fluid-solid coupling calculation of hydraulic structure.The calculation results are compared with that of traditional Westergaad method,the correctness of Fluid 30 element method is verified.The research results show that,(a)the average structural frequency calculated by Fluid 30 element coupling method is 10.93%higher than that calculated by traditional method,and the fluid-solid coupling effect of water body cannot be ignored in seismic analysis of channel structure;(b)the joints between channel lining plates are the weakest part,the stress concentration occurs at each longitudinal joint and larger tensile stress occurs on the lower surface;and(c)the lining structure can be regarded as moving as a whole in earthquake,and the compressive stress on the upper surface of lining is greater than that on the lower surface,but the situation is the opposite when it is close to the joints.