关键词: 循环荷载, 土工格室, 模型试验, 沉降, 极限承载力, 法向累积变形

Abstract: To investigate the performance of reinforced embankment under cyclic and/or static loading, a series of model tests is performed on the geocell-reinforced embankments with various reinforced layers, geocell heights and welding distances, using the loading device of USTX-2000 developed by the GCTS company. The ultimate bearing capacities of the reinforced embankment subjected to both long-term cyclic loading and fixed-number cyclic loading are determined under various operating conditions. The experimental results show that geocell can significantly increase the ultimate bearing capacity of foundation soils and observably reduce the normal accumulated deformation at the critical failure of the top and the middle of slope; for a certain reinforcement spacing, with the increase of the number of reinforcement layers and the height of the geocell, the ultimate bearing capacity can be improved to different degrees and the normal accumulated deformation of critical failure of the top of slope can be reduced; the decrease of the weld space of geocell can also improve the ultimate bearing capacity, and the weld space of geocell has trivial effect on the normal deformation of slope. The number of reinforced layers in fixed spacing has little effect on the vertical cumulative settlement of embankment and can influence the normal accumulated deformation of the top of slope under long-term cyclic loading; the increase of the height of geocell and the decrease of weld space of geocell can reduce the vertical cumulative settlement of the embankment and the normal accumulated deformation of the slope to different degrees. The less the distance to the point of loading, the more significant the influence of reinforcement on the soil pressure of embankment, and the reinforcement increases the stiffness and compactness of soil, so that the soil pressure of the reinforced embankment increases more obviously than that of unreinforced embankment. For the unreinforced embankments, the change of dynamic load amplitude and vibration number can result in the reduction of the ultimate bearing capacity after vibration. For the reinforced embankment, when the dynamic load amplitude is greater than or equal to 30 kPa or the number of dynamic load vibration is greater than or equal to 1 000, the ultimate bearing capacity after vibration is improved.

Key words: cyclic loading, geocell, model test, settlement, ultimate bearing capacity, normal accumulated deformation