Research On Cascading Failure Of Highway Networks Under Capital-constrained Maintenance Scheduling

China’s highway infrastructure is gradually entering the maintenance phase,and highway maintenance will become a long-term task.Under the market-oriented mode of highway maintenance,the highway management department determines the construction party through open bidding,and the maintenance payment methods,construction quality,construction period,and other contents are contracted in a contract,completed by the construction party.The construction party reasonably schedules the maintenance project construction based on the maintenance payment method with the goal of maximizing profits.The maintenance construction process may cause traffic delays due to the closure of some lanes.However,due to a lack of understanding of the traffic congestion and cascading effects caused by maintenance construction,it is difficult to develop effective traffic control measures.Therefore,it is necessary to study the cascading failures of the highway network under maintenance scheduling.This article first establishes a non-linear mixed integer programming model for highway network maintenance based on maximizing the net present value of maintenance contract income.Second,three payment modes for public management departments are set,including a payment mode based on time progress,a payment mode based on maintenance progress,and a payment mode based on maintenance cost,and solved using a genetic algorithm.Then,a traffic flow allocation model based on cascading failures theory is established,and traffic flow evolution under different maintenance scenarios is analyzed using the traffic allocation model.Finally,the cascading failures caused by maintenance scheduling schemes on the highway network are analyzed through a case study.The main conclusions of the paper are as follows:1.The net present value of maintenance contract profits for the maintenance contractor increases linearly with the increase of payment proportion,and exhibits negative exponential decrease with the increase of discount rate.The law of diminishing marginal benefits appears as the maintenance contractor’s financing capability and the number of maintenance teams increase.Under the three different payment models,only simultaneous increases in financing capability and number of maintenance teams can result in a greater net present value for the maintenance contractor.2.The maintenance scheduling plans obtained under the three different payment models have different degrees of road network congestion sensitivity to changes in different factors.When other sensitivity factors remain unchanged,the increase in the number of maintenance teams causes road network congestion to exhibit a linear relationship.With the increase of discount rate,the maintenance scheduling plan under a payment model based on maintenance progress causes the smallest change in congestion fluctuations.With the increase of financing capability,the maintenance scheduling plan under a payment model based on maintenance progress causes the smallest change in congestion fluctuations.With the increase of payment proportion,the maintenance scheduling plan under a payment model based on maintenance costs causes the smallest change in congestion fluctuations.3.Among the three different payment modes of the public administration department,under the change of sensitive factors,a payment mode based on maintenance progress can ensure that the net present value of the benefits of the maintenance construction party is always the largest and the fluctuation of the average congestion level caused by the change of sensitive factors is also the least.This study can provide maintenance scheduling decisions for maintenance contractors and public management departments to reasonably arrange maintenance scheduling plans and cash flow during the highway network maintenance process.