Research On The Dynamic Influence Of Impact Hole On The Pile Foundation Of Adjacent Bridge

In recent years,urban traffic has continued to grow,and urban traffic lines have continued to widen existing roads and bridges and build new lines.Among them,new lines will inevitably cross and merge with existing lines,and the construction of new bridges may affect the structural safety of adjacent existing bridges.This paper starts with the construction of the pile foundation of the bridge substructure and focuses on the dynamic influence of the bored pile during the process of impact formation on the pile foundation of the adjacent bridge.Relying on a construction project of a Nikou interchange,this paper uses numerical simulation and theoretical analysis,from a single homogeneous soil to porous impact in actual engineering and expands the stress and impact of the impact on the pile foundation of the adjacent bridge during the drilling process.The influence of displacement,velocity,and acceleration.The specific research work and results are as follows.1.The impact load is described qualitatively and quantitatively,and the impact load model is established.At the same time,the motion equation of the impact load is described,and the impact load function is simplified to a trigonometric function;based on the wave propagation theory,the vibration wave when the impact load is a point vibration source is explained Propagation characteristics in rock and soil,summarizing the attenuation law of vibration wave.2.According to the actual geological conditions,a single homogeneous pile-soil contact nonlinear calculation model was established,and the changes in the impact vibration source in the horizontal and vertical directions,the magnitude of the impact energy,and the changes in lithology were analyzed and obtained from the adjacent existing piles.The dynamic response law of the foundation under impact load,the vibration velocity and displacement of the pile top,and the change law of the displacement of the pile body are given.According to the results of numerical simulation,the orthogonal test method is used to analyze the sensitivity of the three factors of horizontal spacing,vertical position,and impact energy to the vibration velocity of adjacent existing pile foundations.The sensitivity of dynamic influence parameters is obtained from large to large.The small ordering rules are the impact energy of the ram,the horizontal distance between the ram and the pile foundation,and the position of the depth of the vibration source.According to these research conclusions,the control factors for hole formation in different rock formations at a certain location and the same pile position are put forward,which provides a theoretical basis for the formulation of actual construction plan for impact hole formation and the discussion of safety control standards for existing pile foundations.3.Establish a three-dimensional pile-soil model under impact load according to the actual engineering geology,study and analyze the impact of different punching schemes on adjacent existing pile foundations,obtain the best punching construction plan,and discuss the best plan punching process in detail The influence of the existing pile foundation on the four aspects of displacement,vibration velocity,impact energy and bearing capacity.4.Based on numerical simulation and theoretical calculation,the control system of the Impact of percussion hole construction on adjacent bridge pile foundations is discussed.Based on the analysis of relevant codes,combined with the calculation of the horizontal and vertical bearing capacity of the pile foundation,the control measures of the Impact hole construction vibration before and during the construction on the adjacent bridge piles are proposed,and the vibration of the adjacent bridge pile foundation Impact drilling vibration construction is proposed.Quick criterion.The research results can be applied to related projects and provide references for similar projects.