Study On The Wind Response Of Intermediate Tower For Transmission Line With Foundation Coupled System

Power transmission tower is a kind of high flexible structure building system,which is very important and has huge amount of work.However,with the rapid development of the national economy,and the growing of the level of science and technology,the height and span of power transmission towers are becoming bigger,which are designed and built in nowadays.So,it leads to the wind load becoming bigger and bigger to the power transmission tower.The cases of tower damage and collapse are always appeared,which is caused by strong wind.But when compared with the influence of considering SSI on the transmission tower structure in the role of the earthquake,we find the research production for the influence of considering SSI on the transmission tower structure in the role of the wind load is still deficient.So,this paper using a column foot distance is 15.5 meters and 82.2 meters high ultra-high voltage tangent transmission tower as an example,researching the influence of considering SSI on the transmission tower structure in the role of the wind load.First,this paper design the model of upper transmission tower,foundation and soil at the bottom,selecting a series of important testing parameters,such as the scale ratio of model,the kind of the materials,section forms of the bars,manufacture scheme of model,decorate position of measuring point,the method of simulation for the soil,the number of the test condition,and so on.Meanwhile,building and assembling the power transmission tower,foundatation and soil according to the selected scale ratio,and getting the axial force from four column feet,across-wind and along-wind displacement at the top of tower and accelerated speed on the body of the tower by putting them to the wind tunnel have a test.Then,building a complete numerical model of power transmission tower-foundation-soil by ANSYS,which is a finite element analysis software,and getting the accelerated speed,displacement and axial force from column feet under the different test conditions by changing the value of soil elastic modulus and damping ratio,equivalent static wind load and its direction and position.Finally,the paper compares and analyzes the data result from numerical modeling and wind tunnel test,getting the influence rule of different kinds of response from superstructure of power transmission tower under wind load of different wind speed and wind directions,and soil of different damping ratio and stiffness.If we consider the SSI,the analysis shows that,when the damping ratio of the soil becomes smaller,the response from superstructure will be more bigger;When the damping ratio of the soil becomes bigger,the wind vibration response of accelerated speed from superstructure will be more smaller,but the response of displacement is not changed on the whole;When the stiffness of soil becomes smaller,the response of accelerated speed and displacement from superstructure will be more bigger.So,it is adverse in the structural design of power transmission tower when we consider the SSI,overall.