Research On Construction Cost Control Of Large-scale Bridge Project Based On System Dynamics

Facing the current fierce competition in the field of bridge engineering construction, a powerful guarantee for bridge construction enterprise to get profit and enhance their competitiveness was to improve the level of construction cost control. But there were many problems in the current application and research on the construction cost control of large-scale bridge projects, such as much cost control on the basis of experience, ignoring the internal relation between the cost factors, much research had focused on the operational level that made the cost control lack of dynamic and systemic, being difficult to make reasonable and scientific prediction for the dynamic changes of the construction cost, etc. Based on this, the paper put forward a construction cost control method of large-scale bridge project based on system dynamics, which was supplementary to each other with the current main cost control methods. The purpose was trying to do it for scientific prediction and control for the dynamic changes of the construction cost of large-scale bridge project, so as to achieve the effect of active control in advance.The construction cost control of large-scale bridge project based on system dynamics, which was using the theory of system dynamics to build a construction cost control system model large-scale bridge project, then using Vensim software to run the model and got the simulation results. So, the paper firstly used the theory of system dynamics to analyze the main factors influencing the construction cost of large-scale bridge project and the intrinsic relationship between all the factors, which was used for determining the boundary of the cost control system. Secondly, through the causality relationship analysis of bridge construction project cost and three major objectives and the causality relationship analysis of the change of bridge construction project cost to determine the causal relationship diagram of construction cost control system of large-scale bridge project. Finally, according to the system boundary and the system causal relationship diagram the flow graph of construction cost control system model of large-scale bridge project was drew, then variables in the flow diagram of the model were quantified and all the model variables equation were established, therefore, the qualitative and quantitative analysis methods were synthesized to construct the system dynamics model of the construction cost control of large-scale bridge project.In this paper, the construction project of Yangsigang Yangtze River Bridge was taken as an example, and the construction process of open caisson heightening and sinking was taken as an object of study, relevant information and data which was quantified for the variables in the model was collected and processed, all the variables equation were established and all the constants were assigned in actual data in the model; On this basis, system dynamics simulation software Vensim was applied for simulating the model and dynamic change trend of construction cost in the construction process of caisson heightening and sinking was predicted, then the operability of construction cost control method of large-scale bridge project based on system dynamics was verified; The simulation results of reducing the increased cost which technical risk caused by improving the level of management model of construction technology proved that cost deviation control measures could be found according to the simulation of the model; Finally, by analyzing the simulation results of the model synthetically, the paper put forward some policy suggestions such as enhancing the rationality of establishment of construction scheme and cost plan, strengthening the strict review of labor bidding contract and strengthening the staff training system, etc. that would Raise the level of construction cost control of large-scale bridge project.