为解决综合管廊建设过程中U盾架管机推力预测精度较低且难以有效控制的问题，依托雄安新区启动区某综合管廊工程，以库仑图解法及Mckyes-Ali刮刀切削模型为基础，构建考虑盾壳后边坡坡度、插板切削角、盾-土间外摩擦角的推力计算方法；利用ABAQUS有限元软件建立U盾架管机动态顶进数值模型，并将推力模拟结果与实测结果对比，验证数值模型的有效性。研究结果表明： 1）U盾架管机侧缝回填引起基坑侧壁变形，两侧摩擦阻力峰值由1 453 kN增长至1 985 kN，进而导致推力随推进增长。2）将数值模拟得到的U盾架管机推进时的边坡滑裂面形式以及各分项阻力与理论模型求解结果进行对比，得到推力计算方法预测误差的主要来源是侧面土压力。3）通过引入量纲为一的敏感度函数进行推力影响参数的敏感性分析可知，盾壳后边坡坡度合理施工范围为45°~38°，插板切削角、预留土厚度的合理施工范围分别为30°～50°、0.4～2.0 m，因此应设计可拆卸的插板以控制U盾架管机推力。
In utility tunnel construction, the accuracy of thrust predictions for U-shield pipe-erecting machines is low and the thrust cannot be effectively controlled. To address these challenges, a case study is conducted on a utility tunnel project in the Xiong’an New Area, and a thrust calculation method based on Coulomb theory and the Mckyes-Ali blade cutting model is established. This method incorporates slope gradient, plate cutting angle, and shield-soil interface friction angle. Next, the ABAQUS finite element software is utilized to numerically simulate the dynamic jacking of U-shield pipe-erecting machines. The simulated thrust is then compared with measured data to validate the model’s feasibility. The findings are as follows: (1) Side-seam backfilling leads to sidewall deformation, which increases side friction resistance from 1 453 kN to 1 985 kN, resulting in greater thrust as jacking progresses. (2) A comparison of the simulated data for the slope slip surface and component resistance with the theoretical model reveals that side earth pressure is the main source of prediction error. (3) A dimensionless sensitivity function is introduced to analyze the effects of various factors on thrust. The analysis shows that a slope gradient range of 45°－38° behind the shield is reasonable for tunnel construction. Moreover, the reasonable ranges for the plate cutting angle and reserved soil thickness are 30°－50° and 0.4－2.0 m, respectively. Detachable plates should be designed to control the thrust of U-shield pipe-erecting machines.
