采砂坑对南水北调中线工程渡槽安全运行的影响  

Influence of sand-pits on aqueducts safety operation in Middle Route of South-to-North Water Diversion Project

作　　者：张启义[1,2] 丁留谦[1,2] 解家毕[1,2] 姚秋玲[1,2] ZHANG Qiyi;DING Liuqian;XIE Jiabi;YAO Qiuling(Research Center on Flood&Drought Disaster Reduction of the Ministry of Water Resources,Beijing 100038,China;China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]水利部防洪抗旱减灾工程技术研究中心,北京100038 [2]中国水利水电科学研究院防洪抗旱减灾研究所,北京100038

出　　处：《人民长江》2021年第11期212-218,共7页Yangtze River

基　　金：国家重点研发计划项目(2017YFC0405004)。

摘　　要：南水北调中线工程的运行实践表明,采砂坑对工程的安全运行存在一定的影响。采用定量的方法评估采砂坑对梁式输水渡槽安全运行的影响:①通过采砂坑溯源冲刷等经验计算公式,确定对渡槽影响较大的采砂坑主要分布在交叉断面上游1000 m至下游3000 m范围内;②调查发现,约52.6%的渡槽在上述范围内存在采砂坑,并且个别渡槽交叉断面已经出现下切的情况;③从桩基承载力和进出口建筑物稳定性两方面入手,提出以桩基承载力的降低量和采砂坑距进出口建筑物的距离作为采砂坑影响严重程度的评估指标,制订了相应估计标准,并对所有梁式输水渡槽进行定量评估,发现无论从受影响的渡槽数量还是从影响的严重程度看,采砂坑对南水北调中线工程梁式输水渡槽的整体影响都不严重。根据评估成果,提出了采砂坑的应对措施。The practice shows that sand-pits have some influence on the safety operation of Middle Route of South-to-North Water Diversion Project.And this research mainly focuses on evaluating the influence of sand-pits on water conveyance beam aqueducts with quantitative methods.Firstly,the influence distance of sand-pits was studied through empirical formulas of headward erosion and the results showed that sand-pits with great impact on the aqueducts were mainly located in the range of 1000 m upstream to 3000 m downstream of the cross-section.Secondly,a comprehensive investigation was conducted and the results showed that about 52.6%of aqueducts have sand-pits in the above mentioned scope and some cross sections even had been under incised.Thirdly,risk assessment indices were proposed based on the reduction of bearing capacity of pile foundation as well as the distance between the sand-pits and the import or export structures,and the results of a quantitative assessment indicated that the overall impact of sand-pits on the water conveyance beam aqueducts in Middle Route of South-to-North Water Diversion Project was not serious.Finally,a series of countermeasures were put forward according to the assessment results.

关 键 词：渡槽安全运行 采砂坑 溯源冲刷 桩基承载力 南水北调中线工程 

分 类 号：N8[自然科学总论]