To ensure the safety of deep foundation pit construction and provide scientific basis for controlling surrounding environmental deformation, this study investigates the application of double-row pile support structures in deep foundation pits for water conservancy projects. Based on the principles of synergistic loading, separate calculation of water and earth pressures, and environmental compatibility, Rankine soil pressure theory is employed to calculate water and earth pressures. Design loads are determined by combining permanent loads, live loads, and hydrostatic pressure. The equivalent stiffness method is employed to reduce the double-row piles to a single-row pile equivalent. The elastic foundation beam method is then used to calculate internal forces and deformations within the piles. Stability against overturning and sliding is verified using the moment equilibrium method and sliding plane assumption, respectively. The dewatering design is optimized based on the principles of zoned dewatering and dynamic control, limiting the dewatering rate to a maximum daily water level drop of 0.5m. A three-dimensional numerical model was constructed using FLAC3D software to simulate the coupled effects of deformation in the support structure and seepage field during excavation. The numerical simulation showed that when the pile spacing was optimized, the maximum bending moment in the pile body decreased from 480kN·m to 420kN·m, a reduction of 12.5%. For a deep foundation pit project at a water conservancy hub pump station, a composite system of double-row bored cast-in-place piles and concrete internal bracing was employed, indicating effective deformation control by the support structure. Results demonstrate that double-row pile support structures can significantly enhance deep foundation pit stability through coordinated stress design, refined load calculations, and seepage control measures.

Zhang Zeyu. Application Research of Double-Row Pile Retaining Structures in Deep Excavation Projects for Water Conservancy Engineering. Academic Journal of Engineering and Technology Science (2025), Vol. 8, Issue 5: 113-119. https://doi.org/10.25236/AJETS.2025.080516.

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