组合管拱抗剪刚度的近似计算

Approximate Calculation of Shear Stiffness of Build-up Arched Pipeline Bridge

组合拱式管桥是一种较合理的中型管道跨越型式,分析其结构的稳定性,则应首先确定组合管拱的抗剪刚度。推导其抗剪刚度时,首先要确定桥梁的剪切位移及抗剪刚度。由于组合管拱一般为坦拱,其桁梁的抗剪刚度一般不受拱轴线曲率的影响,按直线桥梁处理。在管道跨越工程中,常用三角形截面组合管拱,由三角形截面桁梁的受力分析图,分析推导出其抗剪刚度。利用相似原理也推出了梯形、菱形截面桁梁的抗剪刚度计算式。所述分析方法可推广到其它直线桁梁的抗剪刚度的计算。

Arched pipeline bridge is a practical, medium sized aerial pipeline crossing. Its shear stiffness shall be determined when analysing its structural stability. In turn, the shear displacement and shear stiffness of the truss are needed to calculate shear stiffness of the pipeline bridge. Because the build-up pipe arch is usally flat, and the shear stiffness of the truss recieves no influence from axial curve of the arch, the truss is treated as a straight line. The pipeline bridge is built up with triangle sections, its shear stiffness can be derived from the stress diagram for the truss with triangle section. Similarly, the formulae of shear stiffness for trusses with ladder and diamond sections can also be derived. This method can be used in other shear stiffness calculations for straight line truss.