Study On Soil Arching Effect Of Pile Supported Reinforced Embankment Based On Modified Finite Element Model

With the rapid development of national economy,the construction of China's highways and railways is in the ascendant,during which the construction of these projects inevitably encounter soft soil foundation.It is difficult to guarantee the stability and settlement of the project on the soft soil foundation directly.In recent years,the pile-supported embankment is a new type of foundation treatment technology.However,the working mechanism of the pile-supported embankment is very complicated.The soil arching is an important part of the pile-supported embankment behavior mechanism.At present,the study of soil arching of the pile-supported embankment is not sufficient.Based on the less field experiment,the research on numerical model needs to be further studied.Therefore,this paper summarizes the existing research results of the pile-supported embankment and compares the commonly used soil arching theory calculation methods.The details are as follows:(1)The field experiment is carried out in Wuchu Road,Ezhou City,and the test equipment such as soil pressure box is arranged on the foundation soil and pile-cap.Thena modified finite element model is proposed.This model ignores the compression of the pile,restrains the vertical displacement of the bottom of the the embankment fill above the pile-cap,simplifies the soft soil into discrete spring units,and simulates the soft soil characteristics with the springs.(2)The results of the modified finite element model are compared with the results of the field test and the Feikang indoor model test,respectively.The correctness of the model is verified.With the calculation results of the modified model,the formation process of the embankment fill arching,the distribution of the stress field and the displacement field of the embankment are studied.The height of the equal settlement section and the height of the soil arching effect are determined.(3)With adjusting the calculation parameters of the modified finite element model,the influence of embankment height,pile spacing,reinforced body,soft soil and embankment filling properties on embankment settlement characteristics,pile load sharing ratio and pile-soil stress ratio is studied.The results show that the relationship between pile spacing and embankment height determines the differential settlement of embankment surface,the laying of reinforced bodies and the improvement of embankment filling properties contribute to the enhancement of soil arching,and the soft soil properties have influence on the height of equal settlement section and soil arching.These are for engineering design reference.