高土石坝裂缝分析的变形倾度有限元法及其应用  

Deformation gradient finite element method for analyzing cracking in high earth-rack dam and its application

作　　者：彭翀[1] 张宗亮[2] 张丙印[1] 袁友仁[2] 

机构地区：[1]清华大学水利水电工程系,北京100084 [2]中国水电顾问集团昆明勘测设计研究院,昆明650051

出　　处：《岩土力学》2013年第5期1453-1458,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.50879040)

摘　　要：土石坝张拉裂缝一般由坝体的不均匀沉降变形引起,是土石坝破坏的主要诱因和表现形式之一。将基于现场沉降监测资料的传统变形倾度法进行了扩展,通过在有限元计算程序中嵌入变形倾度计算模块,发展了基于有限元变形计算的变形倾度有限元法。该方法简洁实用,方便与常规有限元变形计算相耦合,可作为在工程设计阶段分析和估算土石坝是否会发生表面张拉裂缝的实用方法。应用所发展的变形倾度有限元法,以糯扎渡高心墙堆石坝工程为例,进行了坝体后期变形引起坝体表面发生张拉裂缝的敏感性计算分析,探讨了高土石坝变形倾度的分布规律以及与坝体后期变形的关系,发现对糯扎渡高心墙堆石坝,坝顶后期沉降最大值小于坝高0.39%,可作为防止发生坝顶横向张拉裂缝的控制工况。通过工程实例的计算,说明提出的方法可用于高土石坝的裂缝预测分析。Tensile crack induced by differential settlement is the primary cause and typical form in earth-rock dam failure. The classical deformation gradient method is extended by coupling with finite element method. The newly developed deformation gradient finite element method is used to calculate deformation gradient with deformation obtained by conventional FEM instead of on-site monitoring data. This method is simple, and can be used to estimate the risk of tensile cracking in the design phase of dam construction. The possibility of tensile cracking caused by post deformation in Nuozhadu high earth core rockfill dam is analyzed with the method proposed. The distribution rules of deformation gradient and its relation with post deformation are discussed. The analytical results show that： in Nuozhadu high earth core rockfill dam, the post settlement at dam crest is smaller than 0.39 percent of the dam height; so that tensile cracking is almost impossible. According to the case study, the proposed method is applicable to cracking analysis of high earth-rock dam.

关 键 词：土石坝 张拉裂缝 变形倾度法 有限元法 

分 类 号：TV641.1[水利工程—水利水电工程]