地层塌陷区段埋地管道变形与应力分析

已有文献都是基于Winkler地基梁模型来研究塌陷以及悬空等对管道安全的影响,还没有采用其他力学分析模型的报道.分别采用Winkler和理想弹塑性地基梁模型,研究地层塌陷对管道安全的影响.建立了管土相互作用的几何大变形力学分析模型,采用非线性理论对力学模型求解.分析结果表明:在管道的屈服应力较小的情况下,为简化工程计算可采用Winkler模型计算临界塌陷区长度,较弹塑性模型简单,便于工程应用;当地层塌陷区长度较小时,为简化计算可采用Winkler模型分析管道的变形与应力;弹塑性模型可忽略土弹簧刚度对管道分析结果的影响,而Winkler模型则要考虑土弹簧刚度对其的影响.给出了使管道失效的临界地层塌陷区长度,所得结果可供工程设计参考.

Deformation and stress analysis of the buffed pipeline in formation collapse region

The effect of the formation collapse on the safety of the buried pipeline is studied respectively by using the Winkler foundation beam model and the ideal elastic-plastic foundation beam model.The mechanics analysis model of the interaction between pipeline and soil with the large geometric deformation is established,and it is solved by applying nonlinear theory.The analytical results show that,comparing with the Winkler foundation beam model,the ideal elastic-plastic foundation beam model is closer to the practice of the pipeline,but the Winkler model is simple and therefore it is convenient to engineering application;the critical pipeline lengths in the collapse area calculated respectively by using the two model are different,the error between them increases with the increase of the yield strength of the pipeline material,and therefore the Winkler model should be used for calculating the critical pipeline length when the yield strength of the pipeline material is less;the errors of the pipeline deformation and stress calculated respectively by using the two model are less when the critical pipeline length in the collapse area is less,so the Winkler model should be used for calculating the deformation and stress in order to simplify the calculation;the effect of soil spring stiffness on the analytical results of pipeline can be neglected when the elastic-plasticity model is used,but the effect of soil spring stiffness should be considered when the Winkler model is used.