线弹性土壤中埋设悬跨管道的屈曲分析

BUCKLING ANALYSIS OF SPANNING PIPE BURIED IN LINEAR ELASTIC SOIL

建立了两端埋设在线弹性土壤中的悬跨管道的屈曲方程。利用细长梁小挠度理论,建立了含有轴向压力的悬跨段和埋设段管道的弯曲控制方程。基于埋设段管道的刚度和变形特性,建立了符合悬跨段管道实际情况的边界条件。导出了悬跨段管道对称屈曲和反对称屈曲的屈曲载荷方程,通过数值求解给出了不同土壤刚度系数条件下悬跨段管道屈曲载荷。研究表明:悬跨段管道的屈曲载荷系数依赖于土壤刚度系数,简支梁模型只在特定的土壤刚度系数下适用于悬跨管道;在土壤刚度系数很大时,两端固支梁模型才能反映悬跨管道的屈曲特性。建议采用该方法进行埋设悬跨管道的屈曲分析。

Buckling equation of the spanning pipe partially buried in elastic soil is established. Bending equations of the spanning section and the buried section with axial compression are built with small deflection beam theory. Based on stiffness and deformation characteristics of the buried section, more suitable boundary conditions for the spanning section are obtained. Buckling equation of the spanning section is presented in symmetric buckling mode and anti-symmetric buckling mode, and buckling loads under different soil stiffness coefficients are given by numerical method. Research shows that the buckling load coefficient of the spanning pipe is related to the soil stiffness coefficient only. Simply supported beam model is only suitable for the case of specific soil stiffness, and fixed-fixed supported beam model should be adopted for the case of very large soil stiffness. The buckling analysis of the spanning pipe with buried sections can be performed with the proposed method.