Design method for retaining structure of single-row pile combined with double-row pile

With the improvement of urbanization, the environmental conditions of foundation excavation are becoming increasingly complex. Single-row-pile wall as a kind of retaining structure can no longer meet requirements alone, and often work together with strut. In areas where strut is limited, the application of double-row or even multi-row pile retaining structure is very necessary. At present, the acceptance of double-row pile retaining structure is relatively wide, and there are mature design methods. Although multiple-row piles have been used in practice, the calculation method and stress mode have not yet been unified. Based on practical engineering projects, this study systematically investigates the design methodology for retaining systems that combine single-row and double-row piles. Through an analysis of pile-soil deformation compatibility, it is concluded that the synergistic load-bearing mechanism between the rear piles and the double-row piles is primarily achieved through inclined struts. The calculation model is simplified to pile-pile coordinated deformation, and a calculation method is proposed in which rear row piles and double-row piles are calculated separately with deformation coordinated by inclined strut members. Meanwhile, the equivalent model method and finite element method for this retaining system were studied. Comparative analysis with field monitoring data verifies the rationality and feasibility of the proposed method, which can provide references for similar engineering projects.