As a consequence large deformations at the mid-span can occur with risk of aeroelastic instability and structural failure. Analysis of aeroelastic stability also named flutter stability is mostly based on semi-empirical engineering models, where model specific parameters, the so-called flutter derivatives, need calibration from wind tunnel tests or numerical methods. Several papers have been written about calibration of flutter derivatives using CFD models and the aeroelastic stability boundary has been successfully determined when comparing two-dimensional flow situations using wind tunnel test data and CFD methods for the flow solution and two-degrees-of-freedom structural models in translation perpendicular to the flow direction and rotation around the span axis of the bridge section.
某工程基坑为圆形结构,外径29 m , 基坑的开挖深度为33 m ; 采用地下连续墙作为围护结构,初步设计深度为53 m , 厚1 m , 内衬厚0. 6 m , 圈梁截面尺寸1 m ×2 m 。坑底下面有一承压水层,是地层编号分别为⑧3 、⑨1 、⑨2 的粉性土、粉细砂和中粗砂,埋深56. 0 m 以下,其水头高出含水层顶板( ⑧2 层底面)46. 8 m 左右,水头较高,是坑底产生失稳的隐患。