嘉陵江三桥双壁钢围堰结构受力分析

Analysis on Structure Force of Double-wall Steel Cofferdam of Jialing River Bridge III

摘要:

依托蓬安嘉陵江三桥工程，利用MIDAS Civil有限元仿真软件，建立双壁钢围堰的有限元计算模型，考虑结构自重、静水压力、流水压力、施工荷载，分析双壁钢围堰最不利工况下的力学行为响应。结果表明：纵向加劲肋和水平斜撑是双壁钢围堰的受力薄弱部位，优化纵向加劲肋和水平斜撑的布置对保持结构整体性、避免局部屈曲意义重大；增加夹壁混凝土的高度对提高钢围堰的整体受力和减少应力集中具有重要作用。优化设计后经计算，双壁钢围堰的强度、刚度、（整体、局部、抗浮）稳定性满足要求。

Abstract:

Relying on Jialing River Bridge III Project in Pengan, the finite element simulation software of Midas Civil is used to establish a finite element calculation model of double-wall steel cofferdam. The mechanical behavior response of double-wall steel cofferdam under the most unfavorable working conditions is analyzed by considering the structural dead weight, hydrostatic pressure, flowing pressure and construction load. The results show that the longitudinal stiffeners and horizontal skew braces are the weak force parts of double-wall steel cofferdam. It is of great significance to optimize the layout of longitudinal stiffeners and horizontal skew braces to maintain the structural integrity and to avoid the local buckling. Secondly, increasing the height of the concrete in the sandwich wall plays an important role in improving the overall force of the steel cofferdam and reducing the stress concentration. By calculating after the optimization design, the strength, stiffness, stability (integral, local and anti-floating) of double-wall steel cofferdam can meet the requirements.