Japanese Studies on Deterioration of Ballasted Track

SUMMARY SUMMARY In 1950's, studies on track deterioration due to ballast settlement were initiated in Japan. These included those not only on the settlement of ballast, but also on the ballast acceleration which caused the ballast settlement and proposed the coefficient of track deterioration. The design of the track of the Tokaido Shinkansen depended on it. Since then the studies have been continued up to now on the track state related to maintenance work, on the growth of track irregularity and finally on the convergence of track irregularities¨.