大修作业 meaning in English

overhauling

Nevertheless , in chinese railway , there is a shortage of applying heavy duty maintenance machine to conduct the track major repaair for so long time , which resulted in track mudding and hardening
但是，由于我国长期以来一直缺少大型线路养护机械进行线路的大修作业，使目前国内大量线路处于长年失修、翻浆冒泥和严重板结的状况。
The paper analyzes the factors of person , machine , and environment that influence the overhauling work safety of nuclear power station and their interactions , and puts forward the controlling measures of the three factors
摘要分析了影响核电站大修作业安全的人、机、环境因素及其相互关系，并从人、机、环境三方面提出了相应的控制措施。