为解决矩形顶管工程不同泥浆润滑工况下顶进力难以准确预测的问题，结合上海某矩形顶管工程案例实测顶进力变化规律，首先，将顶进过程分成无泥浆润滑、泥浆润滑逐渐发挥以及泥浆润滑充分发挥3种工况； 其次，采用梯形楔形体模型计算矩形顶管迎面阻力，并基于修正太沙基松动土压力理论和泥浆润滑条件，分析3种工况下管土接触状态与界面摩擦因数，考虑管土摩阻力和管浆摩阻力，提出不同工况下顶管侧摩阻力计算方法，在此基础上，形成矩形顶管顶进力预测新方法； 最后，与现场实测数据及现有矩形顶管规范计算结果进行对比。结果表明： 1）提出的计算模型预测精度更高，与实测顶进力误差基本在±15%以内，验证了其合理性。2）初期无泥浆润滑工况下，应采用管土全接触模型和无润滑管土界面摩擦因数计算侧摩阻力；
后期泥浆润滑充分发挥工况下，采用管土一面接触和润滑条件下界面摩擦因数计算侧摩阻力更加准确； 而泥浆润滑逐渐发挥工况处于上述2种工况的过渡阶段，润滑注浆后管土接触状态迅速由全接触变为一面接触。
Accurate prediction of the jacking force in
rectangular pipe jacking projects is difficult under varying slurry lubrication
conditions. To address this challenge, the jacking force variation pattern of a
pipe jacking project in Shanghai, China, is measured. The jacking process is
categorized into three conditions: no slurry, gradual slurry, and full slurry
lubrication. Second, the trapezoidal wedge model is used to calculate the head-on
resistance of the rectangular pipe jacking. Based on the modified Tershaji loose-earth pressure and slurry lubrication conditions, the contact state
and interface friction factor between the pipe and soil under the three slurry
lubrication conditions are analyzed. A new method for predicting the
rectangular jacking force is developed by considering the friction resistances
of the pipe-soil and pipe-slurry
interfaces, thus proposing a calculation method for the lateral friction
resistance under different slurry lubrication conditions. Finally, the results
are compared with the field-measured data and
calculations based on the existing rectangular pipe jacking specifications. The
results demonstrate the following: (1) The proposed model exhibits higher
prediction accuracy, with an error between the proposed model and the measured
jacking force within ±15%, thus validating its
rationality. (2) Under the initial condition with no slurry lubrication, the
lateral friction resistance should be calculated using a full-contact model between the pipe and soil and the corresponding
interface friction factor without lubrication. When slurry lubrication is fully
used in later stages, calculating the lateral friction resistance using the
interface friction factor under lubricated pipe-soil
contact conditions yields more accurate results. Under gradual slurry
lubrication conditions, the contact states between the pipe and soil quickly
change from full contact to one-sided contact.
