Wide variety of joint-type buried pipes are used for urban lifeline facilities, and the characteristics of joints may change due to the effects of aging. If the deformation of joint pipes arranged at regular intervals during an earthquake can be easily calculated, the evaluation of new and existing joint pipes becomes more efficient. Therefore, in this study, a new method is proposed to estimate the characteristics of the joint as the equivalent rigidity so that the analytical solution of the beam supported by the distributed spring can be used for evaluation. Reasonable solutions are shown in this paper obtained by proposed equations.
