系杆拱桥系杆锚下有效索力研究

Study on Effective Prestressing Forces under Anchorage of Tiedarch Bridge

设计对系杆锚下有效预应力和每根系杆张拉力总吨位控制精度有明确的要求,传统的张拉施工工艺难以达到设计的要求.现场对某系杆拱桥的锚下有效索力对比测试结果表明:现有方法施工的系杆锚下有效索力与设计值偏差较大,易造成滑丝、索力不均匀及总的索力偏小的现象,直接威胁系杆拱桥的正常使用.研究结果可为同类型桥梁的设计和施工提供借鉴.

The effective prestressing forces of tied anchorage and total prestressing forces of each tie have specific requirements of precise controlling. Traditional prestressing construction methods could not satisfy the requirements proposed by designer. Effective prestressing forces of tied anchorage at one tied-arch bridge have been tested by different checking methods in practice. The test results show that effective prestressing forces of tied anchorage produced by traditional construction method have a large bias comparing with designed values. The phenomena of gliding tendon, uneven tendon forces and total tendon forces on the small side are easily caused by traditional prestressing method. The normal work statement of tied-arch bridges are threatened by lack of tied forces. The studying results can be used as guidelines for designing and constructing the same type bridges.