Long-Term Settlement Characterization of High-Filling Foundation in the Mountain Excavation and City Construction Area of the Yan’an New District, China

Abstract

Mountain Excavation and City Construction (MECC) represents a prominent anthropogenic endeavor aimed at facilitating urban expansion in the Loess Plateau of China. It is important to comprehend the long-term settlement behavior at MECC engineering sites to effectively assess the project’s success in reshaping landscapes and expanding urban areas. In this study, a typical MECC project, specifically the upstream area of the Liujiagou Valley within the new district of Yan’an City, is selected as a case study to investigate long-term settlement characteristics. The research involved conducting creep tests on soil samples with varying dry densities and moisture content and continuous in-situ monitoring of ground surface settlement at 17 specific points. Furthermore, a numerical model was developed and calibrated using the in-situ monitoring data to predict the long-term settlement. The findings reveal that an increase in soil dry density and a decrease in soil water content contribute to reduced deformation. Notably, settlement primarily manifests within the filled areas, with greater soil thickness exacerbating settlement effects. Over time, cumulative settlement exhibits a progressively diminishing rate of deformation until it attains a stable state. These results provide insights for assessing the long-term stability of MECC projects, facilitating decision-making in future endeavors within this region.