Abstract: Large-tonnage-and-small-radius?U-looped?prestressing?tendons（?UPTs?for?short）have?been?widely?used?in?the?anchorage?zone?of?cable-stayed?bridge?tower.?However,?only?the?research?that?the?elongation?of?steel?hinge?line?and?tensile?stress?has?non-uniformity?is?carried?out?in?current?study?and?the?level?of?elongation?and?tensile?stress?non-uniformity?has?not?been?cleared.?A?novel?method?to?test?the?non-uniformity?is?proposed,?which?is?by?virtue?of?the?statistical?method.?The?non-uniformity?of?small-radius?UPTs?elongation?and?tensile?stress?is?studied?by?the?full-scale?model?test?of?the?tower?anchorage?zone?at?one?cable-stayed?bridge.?The?research?draws?the?conclusion?that?the?non-uniformity?of?small-radius?UPTs?elongation?and?tensile?stress?is?certain?to?exist,?and?the?non-uniformity?level?increases?with?the?number?of?steel?hinge?lines.?When?UPTs?prestressing?system?is?used,?the?tension?stress?limit?should?not?be?controlled?by?the?current?bridge?design?specification,?and?the?value?of?that?should?be?reduced?appropriately.

Key words: concrete cable-stayed bridge , U-looped prestressing tendons , non-uniformity of elongation ;full-scale model test ;

摘要： 大吨位小半径“U”形环向预应力在混凝土斜拉桥锚固区中得到了较为广泛的应用,但目前的研究只是定性 地认为钢铰线伸长量和受力存在不均匀性,不均匀的程度并未研究清楚。在前人的基础上,笔者设计了一种不均 匀性的测试方法,借助统计手段,通过梅溪河斜拉桥索塔锚固区足尺模型试验研究了小半径??U形环向预应力伸 长量不均匀性和由此引起的预应力钢筋受力的不均匀性,研究认为小半径??U形环向预应力伸长量和受力不均匀 存在必然性,且群锚中钢铰线根数越多,这种不均匀程度越严重,张拉控制应力限值不宜再按现行桥梁设计规范取 值,应适当降低。

关键词: 混凝土斜拉桥, “U”形环向预应力, 伸长量不均匀性, 足尺模型试验