为研究上坡条件下矩形顶管开挖面稳定性，基于传统筒仓模型，引入隧道线路坡角对模型进行优化，同时考虑舱内压力在上坡条件下的作用效应，建立矩形顶管上坡掘进开挖面失稳模型。基于极限平衡理论推导隔板土舱压力表达式，讨论土体抗剪强度参数及线路坡角对开挖面稳定性的影响。参数分析表明，土舱压力随土体有效内摩擦角的增大而非线性减小，随线路坡度角的增大而线性增大。与既有理论模型及数值模拟的对比结果表明，提出的理论模型对隧道底部破坏滑移面的预测较好，土舱压力计算值优于既有模型和数值解。依托杭州某上坡掘进矩形顶管工程对失稳模型进行验证，对比结果表明，失稳模型具有较好的工程适应性。

In this study, a tunnel line slope angle is introduced to optimize the traditional silo model, and an instability model of rectangular pipe jacking excavation surface is established considering the effect of pressure inside the silo during uphill tunneling. Both these approaches aim to investigate the stability of excavation surface of rectangular pipe jacking during uphill tunneling. Based on the limit equilibrium theory, the pressure expression of bulkhead soil chamber is derived, and the influence of soil shear strength parameters and line slope angle on the stability of excavation face is discussed. The parameter analysis shows that the pressure of soil chamber decreases nonlinearly with an increase in effective internal friction angle of soil and increases linearly with an increase in slope angle of the line. Comparison of the proposed instability model with the existing theoretical model and numerical simulation shows that the proposed model is superior in predicting the failure slip surface at the bottom of the tunnel. The instability model is verified based on a rectangular pipe jacking project in Hangzhou. The comparison results show that the instability model has good engineering adaptability.