以成都川大下穿人民南路人行通道矩形顶管项目为依托，对富水砂卵石地层矩形顶管机关键技术进行研究。1)为探索同平面多刀盘联合开挖矩形断面技术，采用ANSYS Workbench有限元仿真分析方法对刀盘结构进行优化，得出： 刀盘采用箱体式4辐条结构外加大圆环支撑形式，可满足强度需求的同时有效提高刀盘开口率。2）研究针对大粒径卵石的双螺旋输送机排渣技术，利用ANSYS仿真分析对螺旋叶片厚度进行优化，通过工业性试验表明： 大直径、大节距螺旋叶片设计可有效提高卵石地层的排渣效果，实现450 mm粒径卵石的顺利排出。3）采用正交试验对掘进过程中渣土改良工艺进行研究，获得适应该地层的渣土改良方案。

The key technologies of rectangular pipe jacking machine used in pedestrian passageway on South Renminlu crossing underneath Sichuan University in Chengdu with waterrich sandy cobble strata are studied. The structure of the cutterhead is optimized by finite element simulation analysis method ANSYS Workbench so as to explore the technology of excavating rectangular crosssection using multicutterhead arranged 〖JP〗on a same plane.The boxtype with four spokes + ringform support is adopted for the cutterhead which can meet the strength requirements and improve the opening rate. The thickness of the screw blade of double screw conveyor is optimized by ANSYS simulation analysis. The industrial test shows that the screw conveyor with large diameter and large pitch can effectively improve the mucking effect of large diameter cobble (larger than 450 mm). In addition, the orthogonal test is used to carry out soil conditioning; and proper ground conditioning scheme is obtained.