南水北调中线某节制闸弧形门小开度振动观测与安全评价

Field tests and safety evaluation of radial gate vibration under small opening condition in the Middle Route of South-to-North Water Diversion Project

南水北调中线工程冬季闸门小开度运行,闸后淹没水跃紊动剧烈,为验证小开度下闸门运行的安全性,选取蒲阳河典型节制闸开展闸门振动原型观测。通过测量不同开度下的闸门振动特性,分别采用动应力、振动位移(振幅)和频率作为标准进行振动安全评价,结果表明:闸门最大动应力为1.33 MPa,远小于材料允许应力的20%(约32MPa);最大振动位移15.97μm,小于闸门振动危害程度可忽略不计的上限位移50.8μm;所有测试工况的安全临界振幅A与频率f满足lgA<(3.14-1.16lgf)。上述三种评价准则的判定结果一致,因此,中线闸门小开度淹没出流条件下,闸后水跃紊动引起的闸门振动危害可忽略,闸门结构安全稳定。

In winter,the controlling gates of the Middle Route of South-to-North Water Diversion Project are operated under small opening condition.The submerged hydraulic jump is accompanied by severe turbulence behind the sluice gates.To evaluate the safety of gate operation under small opening condition,we conducted field tests on the Puyang River Gates and measured the parameters of gate vibration under the conditions of different gate openings.The test results indicated that the maximum dynamic stress of the gates is 1.33 MPa,smaller than 20%of the allowable stress,i.e.about 32 MPa.The maximum vibration displacement 15.97μm is less than the upper limit displacement 50.8μm,below which the hazard of gate vibration can be negligible.The relation between amplitude A and frequency f follows lg A<(3.14-1.16 lg f).The evaluation results of the above 3 kinds of criteria are consistent;therefore,the hazard of gate vibration induced by submerged hydraulic jump is negligible,and the gate structure is safe and stable when the sluice gates are operated in small opening condition.