为解决3车道矩形隧道机械化施工难题，对15 m级特大断面矩形掘进机关键系统展开研究。针对特大矩形断面开挖难题，构建组合刀盘分布设计数学模型及其低扰动控制策略，研制出特大断面矩形掘进机低扰动开挖系统；基于驱动转矩数据回归分析，提出引入重叠率的组合刀盘驱动转矩计算方法；为解决盾体超重带来的施工顶进栽头问题，采用基于敏感度的有限元设计方法，实现特大断面盾体轻量化设计；针对大跨度断面土舱压力控制难题，开发出多螺旋输送机协同控制系统及适用于大跨度的主机姿态控制策略，解决特大断面矩形顶管施工姿态及沉降控制等施工难题。同时，针对应用过程中的出渣及管节对中等问题，提出相应的整改方案，最终实现特大断面矩形掘进机的研制及成功应用。

 In order to solve the problems in the mechanized construction of a threelane rectangular crosssection tunnel, the key systems of a superlarge rectangular crosssection pipe jacking machine with 15 m span are studied. To solve the excavation problems of the superlarge rectangular crosssection pipe jacking machine, a mathematical model of combined cutterhead distribution and the control strategy for low interference are built, and a lowinterference excavation system of superlarge rectangular crosssection pipe jacking machine is developed. Based on the regression analysis of the drive torque data, the calculation method for the drive torque of the combined cutterheads with the overlap rate introduced is proposed. In order to solve the problem of nose down due to the overweight shield structure during tunneling, the finite element design method based on sensitivity is used to realize the lightweight design of the superlarge crosssection shield structure. Aiming at controlling the pressure in the excavation chamber of the superlarge rectangular crosssection pipe jacking machine, the multiple screw conveyor coordinated control system and the machine attitude control strategy suitable for largespan pipe jacking machine are developed to solve the problems such as attitude and ground settlement control during the construction of the superlarge crosssection tunnel. Furthermore, corresponding rectification solutions for muck discharge and pipe alignment problems in the application of the pipe jacking machine are put forward. In a summary, a superlarge rectangular crosssection pipe jacking machine has been successfully developed and applied for the project.