Abstract:Research purposes:Cast-in-situ concrete thin-wall cylindrical pile is a new technique for reinforcing soft foundation and it was used for the soft foundation of the Taizhou Railway Station, which was the first time to use it for reinforcing the soft foundation of railway in China. The two monitoring sections were chosen to do in-situ tests, namely one section with cover plate and another with no cover plate. The stressing situation in reinforcing the soft foundation of the two section is analyzed according to the monitored data obtained from soil pressure meter and hole pressure meter and the stressing law in reinforcing the soft foundation with thin-wall cylindrical pile is discovered.
Research conclusions:The cylindrical pile bears the most load of the composite subgrade of thin-wall cylindrical pile and its stressing is mainly from side frictional force. After the cover plate is added to the cylindrical pile, the cylindrical pile can give full play to bearing load. The stressing of soil around cylindrical pile is related to the effective area, and its stress ratio increases with the increase of the load. Application of thin wall cylindrical pile can prevent the soft foundation from lateral distortion by compacting earth. As the anti-horizontal capacity of cylindrical pile’s composite subgrade is good and the anti-side slipping capacity is perfect, the embankment area of high road is good at anti-sliding. The piling quality of the thin-wall cylindrical pile is stable, the single pile’s bearing capacity is good, and the composite foundation has a good bearing capacity of complex piles foundation. The distortion of cylindrical pile is less, especially the post-construction subsidence is small. The strength and rigidity of the reinforced soft foundation are much improved.
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