Research On The Effects Of Dredge Fill On Stress And Deformation Of Bridge Piles In Service

With the speed up of economic development and urbanization,the demand for construction land is growing.To increase the height of ground level and satisfy the requirement of landmark height,it is normally firstly dredge in the coast,river,beach and fill inside the dredge by large area.But this way of obtaining construction land can sometimes bring some engineering problems.If the new dike Crossing Existing Piles,when the embankment load is larger due to the settlement,if the settlement of the soil around pile is larger than the pile settlement,will cause the pile by negative friction effect,to contribute to downdrag in-service piles,which may affect the normal operation of the bridge and even endanger the safety of bridge.This article is based on this background,the research of new embankment marshland in service of Zhanqiao bridge pier.Through numerical calculation,theoretical analysis and normative method,a comprehensive analysis of the effects of the new embankment on the Zhanqiao bridge in service in the.The research work mainly includes the following aspects:1.the research status of the negative friction of pile foundations is summarized and analyzed,including the existing research methods,the factors affecting the negative friction and the depth of the neutral point,and the characteristics of the negative friction and the neutral point have time effect.The theoretical method of numerical simulation is briefly introduced,and the feasibility of the numerical simulation is illustrated.2.consider the different conditions,using three-dimensional nonlinear finite element method,the stress effect of embankment load and deformation of the bridge in service(including the relative pile settlement and pile top and pile bottom horizontal displacement,pile axial stress,beam axial stress,shear stress,pile bending moment and axial force)evolution then,the safety evaluation of bridge piles.3.in service to the Zhanqiao is most concerned about the bridge pile settlement as the representative,to study the sensitivity of parameters.The elastic modulus of each layer soil foundation were changed to Poisson ratio,internal friction angle of main parameters,analyses the relative sensitivity of the pile settlement calculation parameters.In addition,the calculation and analysis of pile settlement considering the most unfavorable combination.4.on the basis of the current standard method,the numerical simulation results are verified by hand calculation.The results show that the numerical simulation results are close to the hand calculation results,which proves the rationality of the numerical method used in this paper.