Analysis on Bridge Pile Foundation Offset and Measures Under Surcharge Load
In view of the pile foundation offset problem,taking a highway bridge affected by asymmetric surcharge load for an example,the pile foundation offset causes and reasons were analyzed.The finite element model was established to analyze the mechanical properties of bridge pile under multiple working conditions,e.g.,before and after being affected by surcharge load,the height of surcharge load,and after unloading correction and treatment.Based on the on-site inspection of upper and lower parts of bridge,soil treatment monitoring,and finite element numerical analysis,the result indicates that the asymmetric surcharge load is the main reason for pile foundation offset.The asymmetric surcharge load around bridge has a certain disturbance to the soil around pile.This causes the soil to have horizontal thrust to the pile foundation,thus causes the pile foundation offset.Unloading the pile-loaded soil until the soil deformation becomes stable can improve the bearing state of existing pile foundation to a certain extent,and play a certain role in rectifying the deviation.By adding reaction anchors to directly apply external forces to the bridge pier structure,and controlling correction direction,the corrective force on bridge pile foundation is provided.The stress release holes are arranged in the longitudinal and transverse directions of pile foundation to effectively release the lateral compressive stress of soil,and reduce the influence of lateral deformation of soil on the pile foundation.Simultaneously,after strengthening the symmetrical pile groups on both sides of original pile foundations,the transverse displacement,bending moment and axial force of pile foundation are greatly reduced.The effect of correcting deviation is obvious,so that the bridge pier can return to the normal state of use.Taking an actual bridge project for an example,the pile foundation,affected by asymmetric surcharge load,is adopted with comprehensive deviation correction schemes,e.g.,drilling pressure relief,excavation unloading,bridge transverse reinforcement,pier longitudinal restoration,and reinforcement by adding piles.The result shows that the deviation correction scheme is effective.
bridge engineeringoffset treatmentfinite element analysispile foundationpile foundation offsetasymmetric surcharge load
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