基于ANP-SD模型的跨海大桥施工阶段造价风险控制与仿真研究OA

In order to reduce the cost overrun risk of cross sea bridge project in the construction stage,this paper discusses the interactive characteristics of cost risk and its control methods.Firstly,the cost risk indicators of 24 construction stages are identified,including project team coordination,mismatching of operation ability,project schedule change risk,design change risk,unreasonable process flow of construction subproject,etc.These indicators may act alone or interactively,resulting in project cost overruns. Then,in order to quantitatively analyze the interaction of these risk factors and their impact on the total cost,a SD model for cost risk assessment of sea crossing bridge construction stage is constructed by using network analytic hierarchy process and system dynamics(SD)method.The network analytic hierarchy process can systematically evaluate the importance of each risk factor and its potential impact on the total cost,and determine the relationship between each factor.The system dynamics method simulates the change and interaction of risk factors in time by constructing a dynamic simulation model. In order to verify the effectiveness of the model,this paper introduces the actual case of HMH sea crossing bridge.Based on this case,an SD model for cost risk assessment of HMH sea crossing bridge in construction phase including control strategy is constructed.The model includes a variety of control strategies,such as reasonable division of bid sections,strict review of on-site visa,strict review of design changes,emphasis on construction bidding,etc.Through simulation,this paper compares the effectiveness of"single strategy control"and"combined strategy control"in reducing cost overrun. The simulation results show that there is a significant interaction between the cost risks in the construction stage,and a single risk control strategy has limited effect in dealing with the complex and changeable risk environment.Single strategy control usually only targets at a specific risk factor,and lacks consideration of other risk factors and their interactions,so it has poor effect in dealing with the comprehensive risks in the complex project environment. In contrast,the use of combination strategy control,that is,the implementation of a variety of risk management measures at the same time,can more effectively reduce the possibility of cost overrun.Through the comprehensive utilization of the advantages of different measures,the combination strategy can reduce the single risk,coordinate and reduce the interaction between various risks,so as to achieve better control effect. The simulation further shows that the combination strategy control can significantly reduce the probability of cost overrun and improve the possibility of successful completion of the project within the budget.This discovery provides a theoretical basis and practical guidance for the cost risk management of large-scale engineering projects such as sea crossing bridges,and helps to improve the project management level and success rate.