钢顶管偏压条件下稳定性分析与控制措施研究

Stability Analysis and Control Measures of Steel Pipe Jacking under Eccentric Loading Conditions

摘要: 为研究偏压条件下钢顶管屈曲稳定性影响规律与控制措施，采用有限元分析方法，基于薄壁圆筒屈曲理论，考虑材料初始缺陷，并引入Winkler弹性地基模型研究了轴线偏差条件下管道长度、壁厚、地层弹性抗力、轴线偏差大小对失稳承载力的影响规律，结果表明：1) 发生轴线偏差的管道长度小于30 m或轴线偏差过大(大于0.4 m)临界失稳荷载迅速下降；2) 随壁厚的增加，临界失稳荷载线性上升，建议常规工况下，t/D取值不低于0.008，复杂工况下，t/D取值不低于0.010；3) 地层弹性抗力对临界失稳荷载影响不大，在软土地层更应注意钢顶管的稳定性问题。同时按是否与人为因素相关系统性总结了轴线偏差影响因素，并基于有限元结果提出对应的量化控制措施。

Abstract: To study the buckling stability laws and control measures of steel pipe jacking under eccentric loading conditions, a finite element analysis method was adopted. Based on the buckling theory of thin-walled cylinders, considering initial material defects and introducing the Winkler elastic foundation model, the influence laws of pipe length, wall thickness, ground elastic resistance, and axial deviation on the buckling load were studied. The results show that: 1) the critical buckling load decreases rapidly when the pipe length with axial deviation is less than 30 m or the axial deviation is too large (greater than 0.4 m); 2) the critical buckling load increases linearly with the increase of wall thickness; it is suggested that the $t/D$ value should be no less than 0.008 under normal working conditions and no less than 0.010 under complex conditions; 3) the ground elastic resistance has little effect on the critical buckling load, and more attention should be paid to the stability of steel pipe jacking in soft soil layers. Meanwhile, the factors affecting axial deviation were systematically summarized according to their correlation with human factors, and corresponding quantitative control measures were proposed based on the finite element results. During construction, the axial deviation should be strictly controlled within 0.05 m to improve construction safety.