Abstract: A finite element model of rockfall-soil-pipe was established to study the influence of rockfall impact on the safe operation of Prestressed Concrete Cylinder Pipe (PCCP).The process of spherical rockfall impact on buried PCCP was simulated on the basis of the calculation of static load condition.By changing the radius and height of rockfall,the stress and plastic strain of pipeline under different rockfall impact loads were examined.Results demonstrated that PCCP under rockfall impact mainly suffered from circumferential tensile plastic damage.Compared with the height of rockfall,the change of rockfall radius had a greater influence on PCCP.At a suspension height of 10 m,the falling rock with a radius over 1.4 m would cause visible cracks in the material with the plastic strain of concrete tube core exceeding 16.0×10^-4 and the plastic strain of mortar over 9.1×10^-4.Under rockfall impact load,concrete tube core first witnessed damage,and then mortar,steel tube,and prestressed steel wire in sequence.After the crack of concrete tube core,steel tube and prestressed steel wire saw rapid increase and yield failure of Mises stress.

Key words: PCCP, buried pipeline, impact road, rockfall, finite element model, dynamic response