混凝土结构裂缝的成因、危害性评估及其修复方法

简述混凝土裂缝的成因及其特点,介绍混凝土裂缝危害性的评估方法,着重讲述混凝土裂缝的修复方法,为施工人员在快捷全面地了解和处理混凝土裂缝方面提供一些帮助.     

货车轮对的运用可靠性

分析了货车轮对在运用中出现故障的原因,提出了提高轮对使用期限的方法和轮对修复的具体措施。     

山区公路水毁修复工程难题处理实例

山区公路水毁，其修复工程并不是按原样修复就能解决问题，提出了7种特殊的修复方法，这些方法都收到了较好的效果。     

Delay Restoration of Single-Track Railway Rescheduling

On the basis of analysis of the principle of delay restoration in a disturbed schedule, a heuristic algorithm for rescheduling trains is developed by restoring the total delay of the disturbed schedule. A discrete event topologic model is derived from the original undisturbed train diagram and a back propagation analysis method is used to label the maximum buffer time of each point in the model. In order to analyze the principle of delay restoration, the concept of critical delay is developed from the labeled maximum buffer time. The critical delay is the critical point of successful delay restoration. All the disturbed trains are classified into the strong-delayed trains and the weak-delayed trains by the criterion of the critical delay. Only the latter, in which actual delay is less than its critical delay, can be adjusted to a normal running state during time horizon considered. The heuristic algorithm is used to restore all the disturbed trains according to their critical details. The cores of the algorithm are the iterative repair technique and two repair methods for the two kinds of trains. The algorithm searches iteratively the space of possible conflicts caused by disturbed trains using an earfiest-delay-first heuristics and always attempts to repair the earliest constraint violation. The algorithm adjusts the weak-delayed trains directly back to the normal running state using the buffer time of the original train diagram. For the strong-delayed trains,the algorithm uses an utility function with some weighted attributes to determine the dynamic priority of the trains, and resolves the conflict according to the calculated dynamic priority. In the end, the experimental results show that the algorithm produces ＂good enough＂ schedules effectively and efficiently in disturbed situations.