Dynamic Characteristics Analysis of High Pier Steel Pipe Lattice Support System in Typhoon Region

According to similar criteria, the on-site lattice support on-site in the typhoon area is 62m high and scaled down at 1: 150 to produce an aeroelastic scaled model of the lattice support. Based on the specifications and the characteristics of the wind field in the area where the project is located, a type A landform is used for wind tunnel tests. Through the measured structural dynamic characteristics combined with the help of the finite element analysis software Ansys, the dynamic characteristics of the lattice support under typhoon wind field were studied. The test results showed that under wind load, the lattice support itself is dominated by second-order low-frequency vibrations. The top end of the bracket is excited with a lower first-order frequency. The difference between the first-order and second-order natural frequencies is small. The support is about H / 3 height or more, which is greatly affected by wind load and speed, and is less affected below 30m; at each wind direction angle, the acceleration response of each measurement point of the support generally increases non-linearly with the increase of wind speed. The response of the measuring point shows a quadratic curve relationship with the wind speed. The acceleration of the measuring point gradually decreases from the top to the bottom. At the same wind speed, the closer to the top, the larger the acceleration. The positive change is more than H / 2, and the change period is unstable. Below 20m, the positive and negative acceleration changes relatively uniformly, the closer to the bottom, the smaller the acceleration period; the maximum value of the wind vibration response at each measurement point occurs under the wind angle of 0 ° and 90 °, the wind resistance generated by the box girder cross section has little effect on the support; at a wind angle of 45 °, the response value of the crosswind and windward wind vibration is similar, and the effect of the crosswind cannot be ignored.