Study On Static And Dynamic Load Transfer Characteristics Of High Speed Railway Pile-supported Geogrid-reinforced Embankment

The construction of high railway on the soft soil foundation may face the problem of too large subgrade settlement if don't take any engineering measures.In order to meet the requirement of the foundation for the settlement,it is necessary to adopt the technical measures such as foundation reinforcement and reinforced cushion layer.The reinforced cushion layer refers to the reinforced coarse-grained soil cushion between the embankment and the foundation to achieve the purpose of adjusting the load distribution on the foundation.The pile-supported geogrid-reinforced embankment is a roadbed with rigid pile reinforcement combined with the geosynthetic cushion layer.GPRS has been widely used in the construction of High Railway Foundation in China because the advantages of short duration,small settlement and small lateral deformation.However,due to the complex load transfer mechanism of pile-bearing reinforced embankment,the influence of the soil arching and the tensile film of the reinforced cushion on the transfer and distribution of the load in the embankment is still needed further study.This paper has studed the transfer and distribution law of the static load and dynamic load in the high speed railway pile-bearing reinforced embankment through the finite element numerical simulation method combined with the field monitoring data.The three-dimensional numerical model of the GPRS under the action of self loading is established,the stress distributions are compared with the indoor test data to verify the correctness of the model.And some models are established to analyze the effect of embankment height,pile spacing and reinforcement layer on the soil arching and the tensile film of the reinforcement.The rail-track slab model and track slab-subgrade model have been established to study the load distribution of the GRPS embankment under the action of high Speed railway operation,the stress-strain distributions under the action of high-speed railway are obtained,and the effects of the height of embankment,the spacing of piles and the number of reinforcement layers on the distribution of stress and strain are studied.The numerical model results of pile-bearing reinforced embankment under the action of load of deadweight and high speed railway operation are studied,and the load transfer distribution law of pile-bearing type reinforced embankment piles under dynamic load is investigated by reference to national norms.