Abstract:
There is a significant potential to apply water-saving ship locks in the northern plain regions of China.However, the chamber of a multi-level distributed water-saving ship lock and the high-level backfill behind the chamber wall can cause substantial foundation settlement in areas with deep soft-soil cover, such as the Luxi Plain, posing risks to engineering safety.Based on the eight-level distributed water-saving ship lock in the Weishan-Xieshan aqueduct crossing the Yellow River, this study addresses challenges such as the thick soft-soil layer, high water head, and high backfill behind the chamber wall.Different rigid pile layout schemes were proposed for the backfill area and the lock bottom foundation as well as connection schemes between the lock chamber and rigid piles, in combination with wide-joint construction techniques.Finite element models were established to analyze the forces and deformations of the lock chamber and piles.The results showed that: The backfill area should be reinforced with a pile layout of uniform length but variable spacing, combined with pile caps.A dense pile arrangement under the chamber wall and a sparse arrangement under the chamber floor are optimal.The wide joint should be sealed during construction of the retaining wall and backfill of the water-saving basin at grades ③~⑤.Compared to other connection schemes, the rigid connection between the chamber wall and piles minimized differential settlement between the chamber floor and wall, making it the best choice.However, under this scheme, the bending moment and shear force of the piles exceeded the bearing capacity of prestressed pipe piles, therefore cast-in-place piles were required to replace them for optimized foundation treatment.Under the optimized treatment, the axial force, shear force and bending moment at the pile top on the outer side of the lock wall were the highest, yet still within the capacity of cast-in-place piles.