摘要
东明黄河公路大桥主桥为(75+7×120+75)m的预应力混凝土刚构-连续组合体系梁式桥,该桥运营多年后出现了梁体开裂和跨中下挠病害。为解决桥梁抗剪承载力不足和跨中下挠问题,主梁采用斜拉体系加固方案,即在原桩基两侧增设桥塔,主梁下部横向增设托梁,托梁与主梁之间通过托架在箱梁底部连接,从桥塔至托梁锚固斜拉索。在主梁加固施工中,新增钻孔灌注桩基础采用回旋钻机钻孔,采用"U形管"法压浆;新增钢构件(托梁、托架和箱内钢支撑)施工主要包括吊装、钻孔、植筋及箱内钢支撑施工;斜拉索按照从中塔到边塔、从短索到长索的顺序分级对称张拉。加固后的荷载试验表明,斜拉体系加固施工改善了桥梁的受力,抬升了跨中截面高度,加固效果明显。
The main bridge of Dongming Huanghe River Highway Bridge is a hybrid system bridge of the prestressed concrete rigid frame and continuous girder with span arrangement（75＋7×120＋75）m.Over the years of operation,the deteriorations like the cracks and midspan deflection have occurred in the main girder of the bridge.To resolve the problems of the insufficient shear capacity and the midspan deflection,the main girder was strengthened by the scheme of the stay cable system.That was,the new pylons were added on the both sides of the existing pile foundations and the joists were added underneath the girder in the transverse direction.The joists and the girder were connected at the bottom of the girder via the corbels and the stay cables were anchored respectively on the pylons and at the joists.In the strengthening construction of the girder,the new bored piles were constructed,using the rotary boring machines and the bases of the piles were grouted,using the U-shape pipe method.The construction of the new steel components（e.g.the joists,corbels and steel supports in the box girder）was mainly the lifting and installation,drilling,reinforcement implanting and the steel support installation.The stay cables were tensioned symmetrically in steps in the sequences from the intermediate pylons to the side ones and from the short cables to the long ones.The load tests for the girder after it was strengthened show that the strengthening construction using the stay cable system improves the load conditions of the bridge,raises up the midspan sections and the effect of the strengthening is quite sound.
出处
《桥梁建设》
EI
CSCD
北大核心
2017年第5期101-106,共6页
Bridge Construction
基金
国家自然科学基金项目(11372165)
交通运输部西部交通建设科技项目(2011318223940)~~
关键词
组合梁桥
连续梁桥
钢箱梁
桩基础
钢构件
斜拉索
施工技术
桥梁加固
hybrid system bridge
continuous girder bridge
steel box girder
pile foundation
steel component
stay cable
construction technique
bridge strengthening
