Dynamics of a shallow underground two-layer pipeline under the moving loads

The mathematical modeling of the dynamics of a two-layer shallow pipeline under the influence of transport load (the load created by an object moving along the pipeline) has been successfully resolved. The pipeline is represented as an extended circular cylindrical two-layer shell with a thin inner (bearing) layer and a thick outer (enclosing) layer situated in an elastic half-space. Dynamic equations of elasticity theory using Lam & eacute; potentials are utilized to describe the motion of the half-space and the enclosing layer of the shell. The vibrations of the bearing layer of the shell are described by the classical equations of the theory of shells. Numerical experiments have considered the case of a moving axisymmetric cylindrical normal load applied to a pipeline (without an enclosing layer and with an enclosing layer of varying thickness and material stiffness). It was demonstrated that if the material of the enclosing layer of the pipeline is more rigid than that of the rock mass, the dynamic effect of the moving load on the rock mass is reduced. [GRAPHICS]