Three-Dimensional Numerical Analysis Of Arching Shape And Effect In Piled Embankment

The pile-supported reinforced embankment that includes four parts: embankment,rigid pile,subgrade,and geogrid,has been widely used in recent years,with its advantages,such as high bearing capacity,small settlement,and rapid construction in the treatment of soft ground of highway and railway.In the pile-supported reinforced embankment,the soil arch which developed due to the big difference of stiffness between rigid pile and subgrade,will cause the transmission of embankment load from subsoil to pile gaps.The three-dimensional soil arch shape and the load transfer feature are the key contents of the paper.This paper has constructed the finite element model of the pile-supported reinforced embankment under the condition of four pile group with the ABAQUS.The main results as follows:(1)The shape of three-dimensional soil arch of the pile-supported reinforced embankment and its development,as well as the effect of the geogrid.The analysis result shows that the shape of three-dimensional soil arch is spheroidicity with four “arch bridge” around.And the shape will not change when geogrid is set but the height will efgfect.The maximum height appears at the centre of four pile.(2)The influencing factors of arch height,including embankment height,pile spacing,size of pile cap as well as soil properties.The results present that the embankment height and pile spacing can affect arch height obviously but the others.(3)The load transfer features of pile-supported reinforced embankment and the role of geogrid.The load is transferred from subsoil to pile cap due to soil arch,while with the cooperation of geogrid the transmission become stronger.(4)The influencing factors of load transfer features,including embankment height,pile spacing,size of pile cap and geogrid.The results come out that all the factors can bring obvious influence.(5)The change of arch shape and load transfer features with different geogrid location and layers.With location rise,the role of geogrid decreases,but the arch height grows.Due to the under geogrid the upper one can hardly contribute.