【作者】 孙涛；

【导师】 李忠学；

【作者基本信息】 浙江大学 ， 工程硕士（专业学位）， 2017， 硕士

【摘要】 2008年严寒的冰雪天气曾导致全国多个地区的通信塔桅出现严重破坏甚至倒塌。随着全球气候变化加剧,极寒极热天气频发,如何克服严寒对通信铁塔的危害是通信基建工作领域迫切需要解决的问题。本文根据《高耸结构设计规范》(GB50135-2006)、《钢结构设计规范》(GB50017-2003)、《移动通信工程钢塔桅结构设计规范》(YD/T5131-2005)等设计规范的规定及相关文献,分析了在严寒环境条件中,通信铁塔受到覆冰荷载、温度作用、风荷载作用下的安全性问题,并分析了厚覆冰对铁塔构件刚度的影响。主要研究内容包括:(1)推导了空间梁单元的刚度矩阵,节点连接刚度均采用一组介于0～1之间的无量纲因子表示,用来模拟实际工程中的半刚性连接节点,保证塔架结构的分析能充分反映其实际的受力情况。(2)以工程实例为基础,通过midas Gen软件对塔桅结构进行了有限元分析。考虑了铁塔因温度大幅变化而引起的温度应力、覆冰条件下风荷载的作用以及覆冰对结构内力的影响,从而揭示极端天气条件对铁塔的受力状态的影响规律。(3)考虑特定天气条件下,有覆冰的结构构件的材料特性,分析了不同覆冰厚度对铁塔刚度的影响,并定性分析了覆冰对塔架结构的影响。更多还原

【Abstract】 The extremely cold weather in 2008 had caused serious damages to the communication towers at various regions in China.To avoid the undesired damages of this kind has been a concern for the structural engineers for years.In this dissertation,the performance of the communication towers is being analyzed with factors of the extreme cold weather,the action of ice load,temperature effect and wind load included,with reference to the requirements of "high-rise structure design specifications," "Steel Design Code","Mobile Communications Engineering steel tower mast structure design specifications" and some other design specifications.Additionally,the effect of ice mass on the stiffness of the communication towers has also been studied.The main contents include:(1)Developing beam element formulation for the members of communication towers.The rotational stiffness of joint is described by a group of non-dimensional factors ranging from 0 to 1 in modeling of semi-rigid connections of communication tower to approximate to the real stress state better.(2)The finite element software Midas Gen is employed to analyze communication tower models,where the effects of temperature stress,wind load and ice load on the internal force of structures are considered.(3)The material properties of structural member under extremely cold weather conditions are considered,and the effect of ice thickness on the communication tower stiffness is evaluated.更多还原