Research On Dynamic Capacity Of Prestressed Concrete Berthing Pile

When large ships berthing at the wharf terminals they often produce enormous impact.In order to reduce the impact and prolong the natural life of the wharf, the anti-collison systems are usually mounted on the wharf pierside. Berthing pile is one of the primary anti-collison equipments in hydraulic structure engineering which is composed of the straight piles drived into earth at the wharf pierside and rubber cushion that is installed between the straight pile and wharf. Its function is to directly bear the impact loading of the ships at the wharf pierside, and absorb the great striking energy of ships by the elastic deformation of berthing pile and deformation of the rubber-pad.Based on the early experiments, this paper studied dynamic capacity of PCBP (prestressed concrete berthing pile). According to the analysis of PCBP's actual working conditions, dynamic response of PCBP are separately deducted, frequency(frequency equation) to all models are given by Winkler model,Pasternak model and the model based on Timoshenko model beam theory. The three models are comparatively analyzed, finds that it is necessary to introduce the Timoshenko model into computation of horizontal response to pile, and recommends the model based on Timoshenko model beam theory as the best model of dynamic response of PCBP. It offers a new method for analysing and designing projects.By ANSYS finite element analysis software, the dynamic nonlinear numerical simulations are separately made corresponding to 20 loading conditions in the model. The effect of deformation ability of concrete strength and initial tensile stress working on the PCBP under the dynamic load is mainly studied. From calculated results,considered the advantage of high-strength concrete and the limitation of its deformation capacity in the prestressed concrete member together,the author suggest that the concrete strength should be C60 and initial tensile stress ( )σcon should be 0. 7fptk. The ship type that PCBP can endure deduced from calculated energy absorption is between 500t and 800t.In practical engineering, if the PCBP combine with other cushioning material, more economical and secure anti-collison systems will be applied, thus better protection will be provided and berthing impact will be reduced to the least.