【作者】 何辉；

【导师】 张社荣；

【作者基本信息】 天津大学 ， 水工结构工程， 2005， 硕士

【摘要】 混凝土面板堆石坝是当今土石填筑坝中很有竞争力和应用前景的一种新坝型。对于复杂加载条件下建立合理的堆石料本构模型,进而采用有效的数值计算方法,对坝体在施工及蓄水条件下的变形和应力进行模拟分析不仅具有重要的学术意义,而且具有很大的工程使用价值。本文全面系统地介绍了现有面板堆石坝应力变形分析的研究成果,同时指出了它的问题及不足。从分析碾压堆石变形特性出发,探讨了碾压堆石的破碎特性、剪胀性、压缩性及它们对面板堆石坝变形的影响,还简要介绍了面板堆石坝堆石体及面板的一些变形特性。本文在考虑坝体中堆石体在蓄水期刚度增加的模式的基础上,根据试验资料对Ducan-Chang E-B模型中的卸载剪切模量和体积模量取值进行了适当修正,一定程度上体现了加荷历史对变形的影响,增强了模型对蓄水加载等路径的适应能力,使计算得到的坝体和面板变形和应力相对较为合理。采用面向对象的编程方法,开发了面板堆石坝三维非线性有限元计算程序系统,可同时完成堆石坝的逐级施工、蓄水后的应力与变形计算。程序中可选用修正的Ducan-Chang E ? B模型或双屈服面模型进行计算,同时设置了接触单元来模拟垫层的影响,并为程序开发了友好的用户界面。利用开发的程序对一高100m的均质坝进行了计算,比较了两种模型的计算结果;并用此程序计算了一个工程实例,验证了研究思想的正确性及软件的有效性和实用性。更多还原

【Abstract】 The concrete facing rockfill dam (CFRD) is a relatively new type of dam withgreat potential and challenging. Establishing reasonable constitutive model of rockfillunder complicated load condition and adopting effective numerical calculationmethod on simulation and analysis of dam deformation and stress during constructionand impoundment not only have important academic sense but also the great usefulvalue in project. In this thesis, describe the research results about deformation and stress analysisof CFRD in existence comprehensively and point out the problem and shortage ofthem. Based on the deformation and stress characteristic of rockfill, discuss thecrushing property, shear and dilatability, compressibility of rockfill and the effect ofthem. Some deformation and stress characteristic of rockfill and slab of CFRD aredescribed briefly.Considering rigidity increase of rockfill during impounding, unloading shearmodulus and bulk modulus in Duncan-Chang E ? B model are revised properlyaccording to testing data in this thesis. The improved model can reflect the influenceto deformation caused by loading history and increase the model adaptability to pathsof impoundment and loading. The deformation and stress of dam body and slab ismore accurate using the improved model.A program system which adopts the object-oriented program method onthree-dimensional nonlinear FEM of CFRD is developed and the program cancalculate the stress and deformation of the dam during the loading step of constructionand impounding simultaneously. In this program, improved Duncan-Chang E-Bmodel and double-yield surface model can be selected and the contact elements areset to imitate the influence of bedding cushion. Friendly user interface is also built.Use the program to calculate a 100 meters high uniform dam with abovementioned two models and compare their different results. The exactitude of researchidea and availability and practicability of the program are proved by calculating aproject with this program.更多还原