OU组合型板桩围护的三维有限元分析

3D-FEM Analysis of a Retaining System Using OU Combined Sheet Pile (OUCSP)

OU组合型板桩是指采用钢管桩(O型)和U型钢板桩通过平面组合和长短组合形成的新型板桩墙。针对某公路下穿地道的OU组合型板桩支护基坑,采用3D有限元软件对如下组合进行了数值模拟计算:1) O型桩与U型桩按O-U-O,O-U-U-O和O-U-U-U-O形式的平面组合;2) O型桩与U型桩按O-U-O的等长度组合和不等长度组合。计算得到O型桩和U型长度组合及平面组合下基坑变形的规律性认识。针对某实际下穿地道工程,有限元分析结果和实测结果进行了对比分析,论证了OU组合型板桩应用于公路下穿地道基坑的可行性。

OU Combined Sheet Pile (OUCSP) for retaining wall is a new type of its kind that is combined with steel pipe, called O pile, and U-section Larsen sheet pile by means of plane layouts such as O-U-O type, or O-U-U-O type, or O-U-U-U-O type, or of different profile layouts such as that with equal length or unequal length. The OUCSP is stiffer than traditional sheet pile, and can be used for deeper excavation with fewer struts accordingly. As such, it is increasingly adopted as the retaining system of the excavations of building foundation pits and underpasses. This paper re-ports a 3D-FEM analysis on an underpass excavation for following types of OUCSP: O-U-O type, O-U-U-O type, and O-U-U-U-O type, O-U-O type with equal length and O-U-O type with unequal length. This 3D-FEM analysis harvests some recognition about OUCSP’s mechanical behaviors when it is used for a practical project, and shows that the calculation agrees rather well with the site monitoring.