埋地管道的横向静力分析耦合模型及其解耦条件

现有埋地管道横向静力分析中的刚性管假设可以实现横向分析与纵向分析的解耦,但往往与实际情况不符.为此,本文根据埋地管道的受力特点,建立了考虑纵向内力影响的横向静力分析耦合模型.基于此耦合模型,结合挠曲线方程与纵向内力的关系,推导出横向分析和纵向分析的解耦条件,为建立解耦模型提供了理论基础.与此同时,一方面为便于实用,另一方面为检验解耦模型的误差,文中针对圆环形管道导出了其横截面剪应力分布规律,给出了埋地管道横向静力分析的实用耦合模型,并结合弹性中心法,建议和提出了耦合模型的实现算法.最后,采用耦合模型对两端固定的埋地给水管道进行了横向内力分析及解耦模型的误差探讨.结果表明,管道两端处纵向剪力对横向内力影响显著,解耦模型误差很大；但随着与管端距离的增加纵向剪力的影响急剧减小,近跨中区域解耦误差几乎可忽略不计.

A coupling model and uncoupling condition of ring static analysis for buried pipes

Although the assumption of rigid pipe is helpful to uncouple radial static analysis with longitudinal analysis,it isn't in accordance with actual condition.In this work,a coupling model of ring static analysis for buried pipes is presented,in which longitudinal bending effects of pipes is involved based on its mechanical characteristics analysis.Combining this coupling model with the relationship between deflection equation and longitudinal internal force,the uncoupling condition between longitudinal and radial static analysis is derived,which proposes the applicable field of the uncoupling model.Meanwhile,in order to improve the practicability of coupling model and check the error of uncoupling model,the shear stress distribution of ring pipes is obtained and a practical coupling model of ring static analysis for buried pipes is given.The implementation algorithm for the practical coupling model is also proposed.At last,ring static analysis of a buried water main with both ends fixed is carried out by the coupling model,together with discussion of error for uncoupling model.It can be found that the influence of longitudinal shear force on radial internal force is obvious at the end of pipe,which means the error for the uncoupling model is unacceptable,but ignorable at the middle of pipe,which manifests that the uncoupling model is accurate enough.