基于热-结构耦合的输电铁塔基础变形特征研究  

Study on Deformation Characteristic of a Transmission Tower Based Using Coupled Thermal-Structural Analysis

作　　者：刘雄军[1] 王永忠[1] 

机构地区：[1]中国电力工程顾问集团中南电力设计院,武汉430071

出　　处：《土工基础》2012年第5期40-42,60,共4页Soil Engineering and Foundation

基　　金："十一五"国家科技支撑计划项目(2008BAC47B02)

摘　　要：利用ANSYS有限元分析软件,建立铁塔地基基础的二维有限元模型,研究南方极端低温条件下温度场与结构场耦合作用时输电铁塔基础与地基岩土体的变形特征。模拟结果表明:地表温度为负温时,地基岩土体发生冻胀使塔基有轻微隆起,且随着地表温度的降低,隆起程度有所增加;在基础底部附近出现应力集中现象,最大剪应力出现在右侧塔基的外侧,且呈逐渐增大的趋势;塔基应变较小,而基础附近的土体变形应变较大,随着地表温度的降低,最大应变均出现在基础顶部的右侧;由于塔基的不均衡受力,最大位移出现在右侧塔基的外侧,最小位移出现在左侧塔基的外侧,且随着地表温度的降低,塔基水平方向的位移变化非常明显,可以看到地基变形破坏的潜在滑动面。With ANSYS finite element software, a 2D finite element model of tower-base was developed to study the deforma- tion characteristic of transmission-tower-base and foundation based on coupled thermal-structural analysis by simulating the ex- treme low temperatures. In the simulation, constant load was applied on the transmission-tower-base, which was the actual biggest load transmission-tower-base experience in the extreme snow and ice conditions in Southern China in 2008, then the temperature was changed to four different conditions. The simulated results show that： because of frost heaving of soil-rock mass, the tower-base has a little upheaval, when surface temperature is below zero. With lowering of the surface temperature, the degree of upheaval increases. Stress concentration appears around the foundation base, with the biggest shear stress at the outside of the right tower-base. Therefore, the biggest vertical displacement occurs at outside of the right tower-base and the smallest occurs at outside of the left tower-base. The horizontal displacement of tower-base changes is also obvious with a po- tential sliding surface formed.

关 键 词：热-结构耦合 铁塔基础 变形特征 ANSYS有限元软件 

分 类 号：TU475[建筑科学—结构工程]