The Impacts Of Bridge-Abutment Embankments On Pile Foundations In The Fujian Putian Soft Soil Area

For the bridge across the soft soil,the piles are easily to be affected by the soil movement nearby(filling or excavation).If without enough consideration,this phenomenon can affect the normal construction and the fuction of the bridge structure.For some structures with the similar situation the research on the interaction of passive piles in soft soil is of highly practical value.Jiang-Kou Viaduct,Red-port 1# Bridge(auxiliary bridge),Red-port 2# Bridge(auxiliary bridge)is located in PuTian JiangKou HanJiang area,which is a project line across the landscape for coastal flood plains geomorphology with a poor soil quality.The project needs to be analyzed in depth for the impact of the roadbed filling on the foundation of the abutment pile.The main researches finished in this paper are as follows:(1)The interaction between pile and soft soil have strong regional affections,in order to make the research conclusion with reliability and applicability,this study carried a 1:1 in-suit test of soft soil interaction at the Putian soft soil foundation area,two piles of different diameter RC-1 and RC-2 were used preliminary for exporing the interaction mechanism between the pile and soft soil.(2)The finite element analysis software Abaqus is adapted to analysis the soft soil foundation under embankment filling.It is concluded that the maximum deformation of soil is proportional to the load.When the soft soil is subjected to external loading,the degree of deformation is positively correlated with the dissipation of pore pressure,and the change trend is basically the same.After the soft soil is loaded,the main deformation occurs in the first two weeks of the external load,and the deformation will stop around the 11 th week,which is equivalent to the time(12 weeks)that the pore pressure tends to stabilize.(3)Simulation of the pile soil effect in accordance with in-situ test was carried out,and the reliability of the model was verified after the comparison with the engineering measured data.Finally,as the pile diameter increases,the deformation of pile body decreases.However,for the position of maximum pile deformation,if only from the depth of burial,the depth of the position increases with the increase of pile diameter.(4)Through the above in-depth analysis of the pile-soil interaction mechanism,Finally,it is suggested that the pressure of the soft soil surface should be less than 180 kPa.Ensure that the heap distance is at least 4m.The diameter of pile foundation should be set within 1.2~1.7m.