简支变连续小箱梁负弯矩区施工优化研究

Research on Construction Optimization of Simple-supported Variable Continuous Small-box Girder in Negative Moment Zone

在传统的简支变连续小箱梁施工过程中,小箱梁负弯矩区过多的张拉槽口及扁锚锚具限制了箱梁预制与钢束张拉的效能。为简化箱梁顶板浇筑施工流程及降低后续顶板负弯矩张拉作业强度,现以上海S7公路(月罗公路-宝钱公路)新建工程为依托,创新性地提出大槽口与新型圆锚锚具工艺,并对其展开标准化试验研究。试验结果表明:在张拉过程中,钢锚垫板纵向位移变化较小且张拉前后混凝土外观良好。这充分论证了该优化方案具有较好的实践应用性。该优化方案能进一步提高工程建设的质量与效率,同时也为桥梁预制拼装技术的发展提供一定的实际工程经验。

In the traditional construction process of simple-supported variable continuous small-box girder,too many tensioning notches and flat anchors in the negative bending moment zone of small-box girder limit the efficiency of box girder prefabrication and steel beam tension.In order to simplify the casting construction process of box girder roof and reduce the subsequent negative bending moment tensile strength of the roof,based on the new Shanghai S7 Highway(Yueluo Highway-Baoqian Highway)Project,the technology of large notch and new round anchor is innovatively proposed,and its standardized test research is carried out.The test results show that the longitudinal displacement of steel anchor plate changes little in the tension process,and the concrete looks good before and after the tension,which fully demonstrates that the optimization scheme has good practical application.The optimization scheme can further improve the quality and efficiency of engineering construction,and also provide some practical engineering experience for the development of bridge prefabrication technology.