School of Civil Engineering of Beijing Jiaotong University, Beijing, 100044, People's Republic of China.
Henan Provincial Transportation Planning and Design Institute Co., Ltd, Zhengzhou, 450015, People's Republic of China.
Sci Rep. 2023 Jan 17;13(1):921. doi: 10.1038/s41598-022-26635-8.
The existing tunnel construction causes stratum deformation, which in turn leads to additional deformation and internal force of the overlying pipeline, thus increasing the risk of pipeline accidents. Then, how to correctly calculate the deformation and internal force of pipeline is the key to pipeline safety evaluation. To this end, this study firstly used the Pasternak foundation beam model to simulate the interaction of pipeline and soil, and divided the pipeline into the void area (i.e., pipeline-soil detachment) and the coordination area (i.e., pipeline-soil is always deformed together) between pipeline and soil. The differential equation of pipeline deflection for the void area and the coordination area were established respectively, and the solutions of pipeline deflection, the internal force of pipeline and the width of pipeline-soil void area were presented. Subsequently, the accuracy of the proposed method was verified by comparing with the available model and field test data, and it is found that the calculation results are too conservative without considering the pipeline-soil voiding phenomenon. Finally, the detailed parametric analysis was conducted. The results show that the pipeline deflection decreases with the increase of the pipeline-tunnel spacing between pipeline and tunnel, the pipeline bending stiffness and the soil elastic modulus, but increases with the increase of the formation loss rate, and the width of pipeline-soil void area increases with the increase of the pipeline-tunnel spacing, the pipeline bending stiffness and the soil elastic modulus.
现有隧道施工会引起地层变形，进而导致上方管道发生附加变形和内力，增加管道事故风险。那么，如何正确计算管道的变形和内力是管道安全评估的关键。为此，本研究首先采用 Pasternak 基础梁模型模拟管道与土壤的相互作用，将管道分为管道-土壤脱空区（即管道-土壤分离）和管道-土壤协调区（即管道-土壤始终一起变形）。分别建立了脱空区和协调区的管道挠度微分方程，并给出了管道挠度、管道内力和管道-土壤脱空区宽度的解。随后，通过与现有模型和现场试验数据进行比较验证了所提出方法的准确性，发现不考虑管道-土壤脱空现象的计算结果过于保守。最后，进行了详细的参数分析。结果表明，随着管道与隧道之间的管道-隧道间距、管道弯曲刚度和土壤弹性模量的增加，管道挠度减小，但随着地层损失率的增加而增大，管道-土壤脱空区的宽度随着管道-隧道间距、管道弯曲刚度和土壤弹性模量的增加而增大。
