关键词: 软土地基, 路基拓宽, 桩网结构, 有限元法, 力学行为

Abstract: In order to get the dynamic construction mechanical behaviors such as pile-net structure implementing and new embankment fractional filling , the dynamic simulation model of expressway embankment unilateral widening on soft ground treated by pile-net structure was estab!ished , comprehensively considering the soil-structure interaction. The critical mechanical responses , such as post construction settlement , lateral displacement , geogrid tension , stability and safety , with and without pile-net structure treatment were compared. The results show that pile-net structure could significantly decrease the post construction settlement and differential settlement at the top of old and new embankment , and effectively slow down the old embankment lateral disturbance impacted by new embankment; geogrid tension reaches the peak value at the edge of pile top , and the potential s!ip surface changes to the side of old embankment from the side of new embankment; stability safety factor keeps relatively high in the full process; the water pressure peak value of excess pore decreases extensively and the dispersing time shortens significantly. Pile-net structure can be used to treat the old embankment widening project on soft ground quickly and safely

Key words: soft ground, embankment widening, pile-net structure, finite element method, mechanical behaviors