考虑费用支付模式的公路网养护调度模型

Maintenance Scheduling Model for Road Networks Considering Payment Modes

为使公路养护承包方获取最大的收益现值,研究了业主不同费用支付模式下的路网养护调度问题.首先,定义了基于时间进度、基于养护进度以及基于养护费用的3种支付模式;其次,构建了以承包方收益现值最大化为目标的养护调度混合整数非线性规划模型,并采用禁忌搜索算法进行求解;最后,通过案例分析验证模型和算法的有效性.研究结果表明:在3种不同的支付模式下,指派给各养护队的路段以及各路段的养护顺序均有较大的差异;当承包方垫资能力达到一定的水平后,继续提升垫资能力不一定能获得更优的养护调度方案,且无法产生更多的收益现值;业主的支付比例与收益现值之间具有近似单调递增的关系,而折现率与收益现值之间具有负指数关系;增加养护队数量可获取更多的收益现值,但其边际收益逐步降低,只有当承包方的垫资能力和养护队数量同步增长时,才能获取更多的收益现值.

To ensure that the maintenance contractor obtains the maximum present value of revenue,the road network maintenance scheduling problem was explored under different payment modes of the client.First,three payment modes,i.e.,time-based payment mode,progress-based payment mode and maintenance-cost-based payment mode were defined.Second,a mixed integer nonlinear programming model for maintenance scheduling was built with the goal of maximizing the present value of the contractor’s revenue,and a tabu search algorithm was used to solve the model.Finally,the proposed model and algorithm were validated by a case study.Research results show that three different payment modes have large differences in terms of the road segments assigned to each maintenance crew and the maintenance sequence of each road segment.When the contractor’s advanced capital reaches a certain level,the continual rise of advance-fund capability may not be able to result in a better maintenance scheduling solution and cannot produce more present value of revenue.The relationship between the client’s payment ratio and the present value of revenue is close to monotonically increasingwhereas there is a negative exponential relationship between the discount rate and the present value of revenue.Increasing the number of maintenance crews can have more present value of revenue,but its marginal benefits are gradually reduced.Only when the contractor’s advance-fund capability and the number of maintenance crews increase synchronously,can more present value of revenue be obtained.