【作者】 卿小飞；

【导师】 赵新华；

【作者基本信息】 天津大学 ， 环境工程， 2012， 硕士

【摘要】 供水管道修复/更换过程通常需要花费巨大的预算并消耗大量的时间,寻找一种高效的程序或方法,如对管道经济剩余寿命进行评估,将有利于管网的维护管理。本文对爆管统计模型进行了详细分析,结合研究区域供水管网的基本信息和管道爆管历史记录,建立了爆管预测EPR模型(进化多项式模型,Evolutionary Polynomial Regression)。EPR模型为分组管道的综合模型,不能直接用来预测单根管道的爆管率,鉴于EPR爆管模型包含综合变量管长和时间因子管龄,建立了单根管道爆管率预测方程。结合管道极限爆管率,求得管道经济最优更换时间。将管道经济最优更换时间作为管道生存时间,选择半参数Cox模型(比例风险模型)对管道进行生存分析,求得了管道生存函数,经分析,管道生存时间符合Weibull分布。采用标准得分残差对模型进行检验,证明管道生存函数符合比例风险假定。管道经济剩余寿命定义为管道从现在算起达到其中位剩余寿命的时间,在此基础上建立了管道经济剩余寿命预测模型,并采用剩余残差对模型进行了检验。最后对管道经济寿命的影响因素进行了分析,确定在本文模型变量的设置情况下,管径和管材为保护因子,管长为危险因子。研究表明,上述方法可以分析出管道经济寿命的影响因素,并建立管道经济剩余寿命的预测模型,且模型具有较高的拟合精度。更多还原

【Abstract】 Since rehabilitation and replacement of water pipes usually require immense budget and time, efficient program or methodology, such as evaluating the economic residual life of pipes, is expected to extremely useful in the maintenance of water distribution system.This paper introduced many statistical models of pipe failure prediction and the EPR (Evolutionary Polynomial Regression) model was developed based on the basic information of water pipes and historic records of pipe breaks in the study area. The EPR model reported here was aggregated, so it cannot be used directly for assessing burst rate at the individual pipe level. But EPR model contained the aggregated variable (pipe length) and the time factor (pipe age), the burst rate forecasting equation of individual pipe was established. The optimal replacement time of a pipe was obtained using the equivalence relationship between burst rate and threshold break rate. The survival analysis based on Cox regression (the proportional hazards model) for pipes were made, which the survival times were defined as the economic optimal replacement times of pipes. Then the survival function was obtained, and the distribution of the survival times of the pipes was considered to have a Weibull distribution. The survival function was proved to obeyed the proportional hazards assumption by analyzing the standardized score residuals. The model for predicting economic residual life of water pipes was constructed based on the definition of economic residual life which calculated as the remaining time until a pipe reached the median survival time from the current time of the analysis. Then the model was test by the deviance residuals. Finally, the main factors affecting the economic life of water pipes were analyzed, the conclusion was that pipe diameter and pipe material were protective factors, pipe length was risk factor in this paper.It showed that the methodology developed in this paper may help utilities identify important factors related to the economic life, and obtain the model for predicting economic residual life of water pipes which was verified to be of better fitting accuracy.更多还原