加劲环式地下埋管非线性有限元屈曲分析  

Nonlinear Finite Element Buckling Analysis of Steel Tunnel Liner with Stiffeners

作　　者：伍鹤皋[1] 胡悦 石长征[1] 鲁志航 李月伟 汪碧飞 WU Hegao;HU Yue;SHI Changzheng;LU Zhihang;LI Yuewei;WANG Bifei(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,Hubei,China;Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan 430015,Hubei,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]长江勘测规划设计研究有限责任公司,湖北武汉430015

出　　处：《水力发电》2022年第5期66-72,共7页Water Power

基　　金：国家自然科学基金资助项目(51409194)。

摘　　要：结合某水电站引水发电系统,对加劲环式地下埋管进行了外压作用下的有限元屈曲分析,研究结果表明:对于加劲环式地下埋管,钢管临界压力随椭圆度等初始缺陷幅值的增加基本呈线性下降;钢管与回填混凝土之间初始缝隙值的增大也将逐渐降低临界压力,尤其当初始缝隙值增大至钢管半径的10/万后,钢管临界压力与加劲环式明钢管临界压力几乎相等。当加劲环间距与钢管半径之比小于2时,加劲环间距对钢管临界压力影响明显,其后加劲环对管壁的约束和临界压力的影响逐渐减小。加劲环高度可以提高钢管临界压力,但在埋管状态下加劲环高度达250 mm后其临界压力基本保持不变。有限元屈曲分析还表明,地下埋管加劲环在管壁屈曲失稳后才可能发生失稳,无需单独校核加劲环自身的抗外压稳定,加劲环截面尺寸可直接根据施工安装条件确定,再由解析法或有限元法计算加劲环间管壁的临界压力,从而确定加劲环的间距。The finite element buckling analysis of steel tunnel liner with stiffeners under external pressure is carried out for a hydropower station.The results show that the critical pressure of steel tunnel liner with stiffeners decreases linearly with the increase of initial defect amplitude such as ellipticity,and the increase of the initial gap between the steel liner and the backfilled concrete will gradually reduce the critical pressure,especially when the initial gap value increases to one thousandths of the radius of the steel liner,the critical pressure of the steel tunnel liner is almost the same as that of the stiffening exposed penstock.When the ratio of the distance between stiffeners and the radius of steel liner is less than 2,the critical pressure of steel liner is obviously affected by the stiffener spacing,and then the influence of stiffener on the constraint of steel liner and the critical pressure is gradually reduced.The height of stiffeners can increase the critical pressure of steel liner,but the critical pressure basically remains unchanged when the height of stiffeners exceeds 250 mm.The finite element buckling analysis also shows that the buckling of the stiffeners of the steel tunnel liner may occur only after the buckling of the shell of the pipe.It is not necessary to check the stability of the stiffener itself under external pressure.The section size of the stiffeners can be determined directly according to the construction and installation requirement,then the critical pressure of the pipe shell between the stiffeners can be calculated by the analytic method or finite element method,so as to determine the spacing of stiffeners.

关 键 词：水电站 地下埋管 加劲环 非线性 屈曲分析 有限元 临界压力 

分 类 号：TV732.4[水利工程—水利水电工程]