One-dimensional settlement characteristics of loess high-fill foundations: insights from centrifuge model tests

The rapid development of western China has intensified the human‑land conflict in the gully regions of the Loess Plateau, prompting local governments to reclaim land through loess high‑fill foundations (LHFF) to support urban construction. Due to the unique engineering properties of loess and the large thickness of compacted fill, LHFF undergo significant settlement during both the construction and post‑construction stages, posing challenges to subsequent engineering works. In this study, centrifuge model tests were conducted to realistically simulate the stress state of LHFF and to continuously capture the overall settlement evolution during and after construction. Three test series were designed by varying moisture content, compaction degree, and fill height. The results show that: (1) the settlement curves of LHFF are fluctuating, and the settlement exhibits hysteresis; (2) total settlement increases with higher moisture content, lower compaction degree, and greater fill height; (3) settlement of LHFF mainly originates from consolidation of loess during the construction stage, accounting for 85–95% of the total settlement, and this proportion increases with higher moisture content, lower compaction degree, and greater fill height; and (4) settlement within LHFF varies with location and depth, and does not increase monotonically with depth. This study is expected to provide a mechanistic reference for engineering practice in loess high-fill projects.