1.前言在日本国铁的百余年历史之中,从大正(译注:1912～1926年)末期开始引进混凝土轨枕已达50余年,由战后开始持续至今的研究工作,也已30年。混凝土轨枕的年铺设量,1962年达100万根,其后10年间,除1963年最大数量为180万根外,每年也都铺设70多万根。现在,在日本国铁枕木总数5600万根中,混凝土轨 1. Preface It has been more than 50 years since the end of Taisho’s introduction of concrete sleepers over the past hundred years of Japan’s national railways. It has been 30 years since the post-war continuation of its research work. The annual laying of concrete sleepers reached 1 million in 1962. In the next 10 years, with the largest number of 1.8 million in 1963, more than 700,000 were laid each year. Now, in Japan, the total number of sleepers 56 million in the concrete rails