世界桥梁
世界橋樑
세계교량
World Bridges
2015年
5期
25-29
,共5页
斜拉桥%混合梁%风洞试验%涡激振动%导流板%排水管%抑振措施
斜拉橋%混閤樑%風洞試驗%渦激振動%導流闆%排水管%抑振措施
사랍교%혼합량%풍동시험%와격진동%도류판%배수관%억진조시
cable-stayed bridge%hybrid girder%wind tunnel test%vortex-induced vibration%guide vane%draining pipe%vibration damping measure
为研究在常遇风速下混合梁斜拉桥的涡激振动性能及抑振措施，以半飘浮体系七跨连续双塔混合梁斜拉桥———重庆永川长江大桥为背景，设计基于1∶50主梁节段模型风洞试验，测试在不同阻尼体系下检修车轨道、导流板对涡激振动性能的影响，并对主梁外挂排水管道的形状进行了优化，最后提出了可显著改善主梁涡激振动性能的抑振措施。研究结果表明：主梁在－3°、0°和＋3°攻角下均发生了明显的涡激振动现象，＋3°攻角下的振幅最大，且远大于规范的容许振幅；向梁底内侧移动检修车轨道，并在其内侧布置导流板可大幅降低主梁的涡激振动振幅；位于斜腹板的圆形排水管道会削弱主梁的气动性能，改用120 cm ×20 cm的扁状排水管道可有效提高颤振临界风速并降低涡激振动振幅。
為研究在常遇風速下混閤樑斜拉橋的渦激振動性能及抑振措施，以半飄浮體繫七跨連續雙塔混閤樑斜拉橋———重慶永川長江大橋為揹景，設計基于1∶50主樑節段模型風洞試驗，測試在不同阻尼體繫下檢脩車軌道、導流闆對渦激振動性能的影響，併對主樑外掛排水管道的形狀進行瞭優化，最後提齣瞭可顯著改善主樑渦激振動性能的抑振措施。研究結果錶明：主樑在－3°、0°和＋3°攻角下均髮生瞭明顯的渦激振動現象，＋3°攻角下的振幅最大，且遠大于規範的容許振幅；嚮樑底內側移動檢脩車軌道，併在其內側佈置導流闆可大幅降低主樑的渦激振動振幅；位于斜腹闆的圓形排水管道會削弱主樑的氣動性能，改用120 cm ×20 cm的扁狀排水管道可有效提高顫振臨界風速併降低渦激振動振幅。
위연구재상우풍속하혼합량사랍교적와격진동성능급억진조시，이반표부체계칠과련속쌍탑혼합량사랍교———중경영천장강대교위배경，설계기우1∶50주량절단모형풍동시험，측시재불동조니체계하검수차궤도、도류판대와격진동성능적영향，병대주량외괘배수관도적형상진행료우화，최후제출료가현저개선주량와격진동성능적억진조시。연구결과표명：주량재－3°、0°화＋3°공각하균발생료명현적와격진동현상，＋3°공각하적진폭최대，차원대우규범적용허진폭；향량저내측이동검수차궤도，병재기내측포치도류판가대폭강저주량적와격진동진폭；위우사복판적원형배수관도회삭약주량적기동성능，개용120 cm ×20 cm적편상배수관도가유효제고전진림계풍속병강저와격진동진폭。
To examine the vortex‐induced vibration property and the measures to suppress the vibration of hybrid girder cable‐stayed bridge under common wind speeds , the Yongchuan Changjiang River Bridge in Chongqing ,a seven‐span two‐pylon continuous hybrid girder cable‐stayed bridge of half floating system ,was taken as the study background .The wind tunnel test based on the 1∶50 sectional model of the main girder was designed ,to test the influence of over‐hauling car tracks and guide vanes on the property of vortex‐induced vibration under different damping systems .The shape of the external draining pipes on the main girder was optimized ,and vibration damping measures that can markedly improve the property of the vortex‐induced vibra‐tion of the main girder was proposed .The results of the study show that distinct vortex‐induced vibration was found in the main girder when the wind attacking angle was respectively at -3° ,0° , and + 3° .The maximum vibration amplitude appeared when the attacking angle was + 3° ,far greater than the allowable value in the code .The amplitude of the vortex‐induced vibration of the main girder can be considerably deceased by moving the overhauling car tracks towards the inner side of the base of the main girder and installing guide vanes at the inner side of the main girder . The circular draining pipes at the diagonal webs will exacerbate the aerodynamic property of the main girder ,therefore ,the 120 cm × 20 cm flat draining pipes are chosen ,w hich can effectively im‐prove the critical flutter speed and reduce the amplitude of vortex‐induced vibration .
