波纹钢板在隧道明洞结构中的应用研究

Research on Application of Steel Corrugated Plate in Open Tunnel Structure

为研究波纹钢拱圈式隧道明洞结构的力学性能,为该类型隧道明洞结构的应用提供理论依据,以某隧道窗孔式明洞为工程背景,采用有限元数值模拟方法进行受力分析。首先,分析明洞结构中基础底座、混凝土拱圈和波纹钢拱圈的应力分布特点;其次,从弯矩、轴力和位移3个方面研究波纹钢板的厚度对该明洞结构受力的影响;最后,从弯矩、轴力和位移3个方面研究钢拱圈不同矢跨比对该明洞结构受力的影响。研究结果表明:1)基础底座的内外墙根部截面应力较大,为结构受力最不利位置,混凝土拱圈和波纹钢拱圈在拱脚和拱顶附近位置处受力较大; 2)随着波纹钢板厚度的增加,内外墙底部截面的弯矩均有所减小;外墙底部截面的轴力有所减小,而内墙底部截面的轴力有所增加;钢拱圈的横向和竖向位移均有所减小; 3)随着钢拱圈矢跨比的减小,内外墙底部截面的弯矩不断增加,且内墙底部截面弯矩增加更为明显;内外墙底部截面的轴力不断减小;钢拱圈的横向位移不断减小,竖向位移出现先减小后增加的趋势。

In order to study mechanical characteristics of open tunnel structure with steel corrugated plate arch ring, and provide theory basis for application of this type of open tunnel structure. Taking an aperture open tunnel as engineering background, the finite element numerical simulation method is used to analyze the force. Firstly, the stress distribution characteristics of foundation base,concrete arch ring and steel corrugated arch ring are analyzed;Secondly, the influence of the thickness of steel corrugated plate on the force of the structure is studied from three aspects of bending moment, axial force and displacement;Finally, the influence of different rise-span ratio of steel arch ring on the stress of the open tunnel structure is studied from three aspects of bending moment, axial force and displacement. The results show that:(1)The section stress at the root of the inner and outer walls of the foundation base is large, which is the most unfavorable position for the structural stress. The concrete arch ring and steel corrugated arch ring bear large stress near the arch foot and the arch roof;(2) As the thickness of corrugated steel plate increases, the bending moment of the bottom section of the inner and outer walls decreases. The axial force of the bottom section of the outer wall decreases, while that of the bottom section of the inner wall increases. The horizontal and vertical displacements of the steel arch ring are reduced;(3)With the decrease of the rise-span ratio of the steel arch ring, the bending moment of the bottom section of the inner and outer walls increases constantly, and the bending moment at the bottom of the inner walls increases more obviously. The axial force of the bottom section of the inner and outer wall decreases constantly. The transverse displacement of the steel arch ring decreases constantly, and the vertical displacement decreases first and then increases.