| Against the backdrop of urban renewal, anchor-reinforced static pressure piles were employed to reinforce the existing independent foundations of buildings to meet their foundation strengthening requirements. By integrating field monitoring with ABAQUS finite element numerical simulation, this study analyzed the ultimate bearing capacity, load distribution ratio within the piles, and influencing factors of the composite foundation system after reinforcement with anchor rod static pressure piles. Results indicate that as the superstructure load increases, the pile cap load of the composite foundation steadily rises. Once the pile cap load stabilizes, the load-sharing ratio of the anchor-reinforced static pressure piles reaches 40.12%. The discrepancy between the simulated and theoretical values for the ultimate bearing capacity of a single pile was 2.11%, the discrepancy between the simulated and theoretical values for the settlement of a single pile was 8.58%, and the deviation between the simulated and monitored values for the pile head reaction was 5.73%, thereby validating the reliability of the model. The ultimate bearing capacity of the reinforced composite foundation significantly improved. Under the 6-pile configuration, the ultimate bearing capacity increased by approximately 87.80% compared to the original independent foundation, demonstrating remarkable settlement control. Furthermore, increasing the number of piles substantially enhances both the ultimate bearing capacity and settlement control capability of the composite foundation. Consolidating the surrounding soil at the same time strengthens the soil mass and progressively reduces the rate at which the pile load-sharing ratio grows. Within the same bearing layer, increasing pile length enhances the composite foundation's ultimate bearing capacity and pile load-sharing ratio, though the improvement is relatively limited. Increasing pile diameter can effectively enhance the ultimate bearing capacity of composite foundations and the load-sharing ratio of piles. Increasing the strength of the bearing layer soil can improve the ultimate bearing capacity of composite foundations and significantly reduce overall foundation settlement; however, due to the increased bearing capacity of the independent foundation itself, the load-sharing ratio allocated to the piles will decrease. Furthermore, increasing pile spacing can mitigate the pile group effect, thereby enhancing both the ultimate bearing capacity of the composite foundation and the load-sharing ratio among piles. |
