基于三维有限元的防洪闸底板内力计算方法研究

Research on the Calculation Method of Flood Gate Soleplate Internal Force Based on 3D Finite Element Method

随着防洪闸等水利工程趋向于大型化与复杂化,传统方法很难准确计算大体积复杂混凝土结构截面应力应变状态。针对上述问题,根据某防洪闸工程实例,利用Midas GTS NX软件建立了防洪闸及其附属结构的三维有限元模型,模拟分析了不同工况下防洪闸闸室底板变形特征。结合基于文克勒地基梁的基床系数法和基于应力积分方法的三维有限元法,对比研究了防洪闸底板内力特性,发现基于应力积分的三维有限元法能够很好地模拟实际工程结构的受力特性,而基床系数法由于忽略了边荷载作用,低估了底板的最大负弯矩;利用三维有限元模型进一步探究不同范围边荷载单独作用下闸室底板结构变形特征与内力特性,结果表明闸室水压力和相邻闸室结构荷载的影响最大,在实际计算中垂直水流向1.5倍基础宽度范围内边荷载作用应重点考虑。

With the development of hydraulic engineering such as flood gates to the direction of large-scale and complication,the traditional analysis method is difficult to calculate the stress and strain on the cross section of mass concrete structures.In order to solve the above problem,taking a flood gate project as study case,the three-dimensional finite element model of flood gate and its attachment structure are established by using Midas GTS NX software to simulate and analyze the deformation of the flood gate soleplate in different design conditions.Combining the subgrade coefficient method based on the Winkler elastic foundation beam and the three-dimensional entity finite element method based on the stress integral method,the comparative analysis of the internal force of flood gate soleplate are conducted,which shows that the three-dimensional entity finite element method based on the stress integral method can well simulate the mechanical characteristics of actual engineering structures,and the maximum negative bending moment is underestimated by the subgrade coefficient method because the side load is ignored.For further research about the effect of side load,the change law of deformation and internal force of flood gate soleplate under different side load cases are studied,and the results show that the water pressure and the load of the adjacent flood gate structures have greatest influence.So within 1.5 times the foundation width,the side load which is perpendicular to the flow direction cannot be ignored.