Risk Analysis and Management of Second Railway Line Construction Adjacent to the Existing Lines

To meet the increasing demands of freight and passenger volume, many second railway lines adjacent to the existing railway lines are being (will be) built in China. But the construction process is different and more complicated for the second railway line than the new railway line, and the risk control is a big problem for the practitioners. In this paper, based on second railway line construction practices, the risks are summarized and divided into two main types, construction works contents and specialties, and each type is divided into several subtypes. In all subtypes, some typical cases are illustrated and analyzed. During the risk analysis for each case, a method named "4M4E" is used, in which the "4M" discovers accident causes from four aspects: man, machine, media and management and the "4E" puts forward corresponding measures from four aspects: education, engineering, environment and enforcement. Through such analysis, the main risks in the construction process are shown in two tables and it is clear and easy to understand and trace. In the last, a PowerPoint risk analysis program is developed. The practices show that the "4M4E" method is suitable to such construction works.