Analysis on the Problems and Countermeasures of the Electromechanical Contract Variation in Guangzhou Metro Construction

Changes of electromechanical devices have an influential effect on subway construction costs. This paper finds some laws and problems after empirical studying 91 engineering change orders of the station equipment installation engineering in Guangzhou metro. On the quantity and charge, the changes show a large quantity and a low charge. The charge of the biggest single change is less than 1 million Yuan among them. On the reasons, the design factor occupies the dominant position; its proportion is up to 50% in the total. Second is the coordinate factor between the owner and the external. On the distribution of the charge, the variation of the installation engineering is the most intense. The variations of the construction and decoration engineering are relatively mild. The coefficient of variation is 1.18; it has a large discreteness. On the approval process, approval time shows a low linear correlation with the changed charge. In order to strengthen the control of the changed charge and increase the efficiency of the contract change management, we suggest that the metro construction department should enhance the management in the design phase, focus on the change of the installation project, simplify the approval process of the changes which have a small charge, and control the approval process of the changes whose charge is above 100000 Yuan. After these, the impact of the changes on the project construction will be reducd. And the metro project construction will likely go on smoothly.