ABSTRACT
In this paper consist of three parts; 1) it is obtained the statistical nature of the deterioration more than the actual inspection data of bridges and tunnels. 2) Log–normal distribution shows excellent fit with various data on the durations of disabilities, irrespective of their severity. Finally, the deterioration of tunnel concrete linings is mathematically described by a random differential equation driven by compound Poisson process. And also, we are developed a similar stochastic model describing random bridge deck slab degradation, where we try to apply a phenomenological law proposed by Kachanov in the field of fracture mechanics.
