关键词: 软土路基, 路基沉降, 填筑高度, 填筑速率, 排水固结效果

Abstract: The settlement in the soft soil subgrade project seriously affects the construction schedule and the service life of the roadway. The main factors that cause the settlement in the embankment include the embankment height, filling speed and the drainage characteristics of subgrade. In order to study the influence degree of these factors on the settlement in the embankment on soft soils, this paper uses the PLAXIS finite element software to establish the two-dimensional plane model of soft soil embankment, and the embankment is simulated by the Mohr Coulomb model. The creep model of soft soil is used to simulate the soft soil. The analysis results show that: ① the embankment height has an obvious effect on the magnitude of settlement in soft soils, and there is a good correlation between the two. With the increase of embankment height, the vertical pressure in the soft soil increases, which increases the settlement of subgrade; ② the settlement in the soft soil subgrade is mainly in the consolidation stage of soft soil, when the consolidation is completed, The settlement tends to stable. With the acceleration of construction filling rate, the settlement rate tends to stable. When the average filling rate is 5 cm/day, the filling effect of subgrade is the best; ③ when the vacuum drainage preloading method is adopted for constructing the embankment in soft soil, the distance between drainage path is one meter, and the vacuum pressure is 80 kPa, the drainage effect is the best, and the embankment reaches the stable settlement pattern quickly.

Key words: Embankment over Soft Soil, Subgrade Settlement； Embankment Height； Filling Rate； Drainage Characteristics