Monitoring of Wind Effect on Membrane Roof of EXPO Axis

Due to its characteristics of lightweight, high-strength and good mechanic performance, membrane structure is broadly used in long span structures. However, it is very sensitive to wind and prone to be excited in turbulence flow. In the past Expo Shanghai 2010, this kind of structure was used as roof for Expo Axis, which is a semi-open building with the roof designed with a large and light cable-membrane structures. The width of Expo Axis is about 90m, the length is 1045m. In this paper, monitoring of wind effect of the structure is addressed. First of all, the measuring points and corresponding distribution are introduced. Through several months’ monitoring, some data were acquired, such as wind speed, wind pressure and acceleration. Through random decay technique, combined with eigensystem realization algorithm, the frequencies and damping ratio of the structure were obtained. Identification results show that the frequencies and damping ratio are in a certain range. The damping ratios range from 0.0160 to 0.339, which are consistent to our common understanding.