Research On Dynamic Response Of Pile Socketed In Weak Rock Under Ship Impacting

Ship-bridge collision is a series of complicated dynamic responses involving the ship, bridge andsoil. Soil structure interaction has a great influence on ship-bridge collision. Considering soil structureinteraction, the dynamic response of single pile socketed in weak rock is studied influenced by shipimpacting.First, the experimental models including ship, pile and soil are built by referring the reality with a1:100ratio and collision experiment is carried out. Second, a more veritable FEM model is createdbasing on existing study, and finite elemental analysis is employed to obtain the dynamic responseduring the collision simulation. Finally, the factors influencing the maximum ship impacting force isanalyzed and the formula of the ship force is obtained.The factors influencing the dynamic response of pile are analyzed, which include weight ofship,speed of ship, weight of cap, vertical load on the cap, diameter of pile, property of rock and soilaround pile, length of pile above the ground and elasticity modulus of pile. Speed of ship, weight ofcap, diameter of the pile and elasticity modulus of pile have a significant effect on the maximumdisplacement and the maximum acceleration of pile top and the maximum stress of pile body; Weightof ship and length of pile above the ground have little effect on the maximum acceleration of pile top;The property of rock or soil around the pile has little effect on the maximum stress of pile body; Thevertical load on the cap has little effect on the maximum displacement pile top.While the influence of soil structure interaction is considered, the maximum ship impacting force isstudied. The maximum ship impacting force is proportional to the Square Root of weight of ship andspeed of ship, in exponent with diameter of pile and shear modulus of soil and length of pile above theground. A fitting formula is derived after the relationship between the maximal ship impacting forceand the five parameters has been established. The fitting formula is used to calculate the maximumship impacting force comparing with the other formulas of the codes including AASHTO,VROUWENVELDER ACWM and China railway bridge and culvert design specifications. Theresults of the fitting formula are much closed to that of VROUWENVELDER ACWM (K=5).