大型升船机塔柱简化结构的抗倾覆稳定性分析

Analysis of anti-overturning stability of simple model of large-scale ship lift tower

鉴于齿轮齿条式升船机过坝速度快、运行安全可靠,已在我国的大型水利水电工程中得到广泛应用。由于升船机支承塔柱高宽比通常大于6,在水平地震荷载作用下,受到很大的倾覆力矩,使得基础的一侧发生破坏,当结构倾覆力矩超过由结构自重产生的恢复力矩时,结构将发生转动,当转角大于临界倾覆角时结构将会发生倾覆。因此需要评价升船机塔柱结构在强震作用下的转动稳定性。本文基于MATLAB 7.0,编制了摇摆反应控制方程求解程序,利用该程序对大型升船机塔柱简化结构进行了抗倾覆稳定性分析。研究表明:地震波的频谱特性、高宽比、结构尺寸对结构抗倾覆能力有很大影响。应重点关注升船机塔柱结构底部拉应力集中区以防止应力过大引起底部脱开而发生摇摆失稳。

The vertical gear-rack ship-lift has been widely applied to large water and hydropower projects in China, due to its speed, safety and reliability. Since the width-height ratio of tower structure of ship lift is typically greater than 6, under horizontal ground motion, the resulting overturning moment of tower struc-ture is so large that the interface between structure and foundation will be destroyed. When overturning mo-ment exceeds restoring moment capacity,structure will tip about an edge of its base. It is necessary to ana-lyze the anti-overturning stability of tower structure of ship lift under strong ground motion. Based on MAT-LAB 7.0 platform, the solving program of rocking equations of rigid bodies has been developed. After verifi-cation, the overturning stability of simplified tower structure of ship lift has been analyzed in this paper. The results show that the characteristics of earthquake waves, width-height ratio and sizes have important impact on overturning stabilities of tower structures. More attention should be paid to the concentration zones of tensile stresses at the bottom of tower structure to prevent bottom disengagement from resulting rocking instability.