Study On The Effect Of Extremely Cold Snow And Ice Weather On Service Performance Of Telecommunication Towers

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.