The Effects of Ground Anchor Prestressing on Pile Group Reaction Force Redistribution and Settlement as Permanent Foundation of High-Rise Building Using 3D FEM

The use of ground anchors to hold back retaining structures is distinctly different from reinforced soil, which aims to bind a soil mass together to form a gravity structure. Ground anchors comprise a smaller number of more widely spaced elements that are highly stressed before the retaining structure is commissioned (Clayton et al. in Earth pressure and earth retaining structures. CRC Press, [1]). In case studies in Indonesia, ground anchors were installed as a permanent foundation on the building foundation to resist the tension load during the earthquake (Danziger et al. Eng Geol 87(3–4), [2]). The study was conducted on Hospital Project in Jakarta, Indonesia. After the building reach topping-off, the prestress of the anchor conducted as part of the design load. 3D Finite Element Analysis is used to simulate the effects of the prestress force on the foundation system. The analysis shows that the prestress makes the bulb pressure of the foundation system larger and the settlement higher. The adjacent pile forces change significantly due to the ground anchor prestressing. The pile adjacent to the ground anchor receives additional compression stress due to the additional tensile load of anchor prestressing. This paper will discuss the prestress effects of the ground anchor as a permanent foundation towards the foundation system.