南水北调中线典型输水建筑物表面降糙防护探析

A Probe into the Surface Roughness Reduction and Protection of Typical Water Conveyance Structures in the South-to-North Water Diversion Middle Route Project

南水北调中线工程是缓解北方水资源短缺的战略性基础设施,通水以来已发挥出巨大的综合效益。工程输水线路长、河渠交叉建筑物众多,随着工程运行时间的增加,受冻融变化、混凝土的碳化、泥沙淤积等不利因素的影响,输水建筑物过流表面的不平整度逐渐增加,可能对输水系统的过流能力产生一定的风险。结合中线工程特点,选取典型输水渡槽作为试验对象,探索研究通过在建筑物表面喷涂一种无毒无害且稳定性高的纳米材料,以期在防护混凝土同时降低建筑物表面粗糙度。针对工程实际运行情况,提出了试验测流检测和调度配合方案,在保障正常安全供水前提下成功实施,并进行了试验前后流态对比、水力学模拟计算,分析评估了试验效果。结果表明,该方法对改善渡槽输水流态、降低渡槽表面糙率、提升过流能力有一定的效果。该研究可对类似长距离调水工程降糙防护等工作具有借鉴意义。

The South-to-North Water Diversion Middle Route Project is a strategic infrastructure to alleviate the shortage of water resources in the north,and the project has played a huge comprehensive benefit. The water transmission line of the project is long and there are many river canal crossing buildings. With the increase in project operation time,affected by adverse factors such as freeze-thaw change,concrete carbonization and sediment deposition,the unevenness of the overflow surface of water transmission buildings increases gradually,which may pose a certain risk to the overflow capacity of the water transmission system. Combined with the characteristics of the middle line project,this paper selects the typical water conveyance aqueduct as the test object,and explores and studies the spraying of a non-toxic,harmless and stable nano material on the surface of the building,in order to protect the concrete and reduce the surface roughness of the building at the same time. According to the actual operation of the project,the cooperation scheme of test flow measurement,detection and dispatching is proposed,which is successfully implemented on the premise of ensuring normal and safe water supply. The flow pattern comparison before and after the test and hydraulic simulation calculation is carried out,and the test effect is analyzed and evaluated. The results show that this method can improve the water flow pattern of aqueduct,reduce the surface roughness of aqueduct and improve the flow capacity. The study can be used as a reference for roughness reduction and protection of similar long-distance water transfer projects.