超强高韧性树脂钢丝网混凝土及在预应力板梁桥加固设计研究

Bridge plays an important role in the national economy and people's life as a throat engineering of highway traffic system. The prestressed concrete plate beam bridge is one of the largest number of bridge, but sometimes the structure can not meet the bearing capacity and normal serviceability requirements because of the quality of design and construction, material aging, rising load level and the neglect of maintenance and repair, which needs reinforcement. The project is based on the stiffness, ductility and bearing capacity of plate girder and develops the study of HTRC(High Toughness Resin Concrete with Steel Wire Mesh) and reinforcement design of prestressed concrete plate beam bridge, which has very important significance. Around new material and reinforcement design, which has become a frontier and hot topic, using material test, theoretical analysis, and indoors full-scale load test, we evaluated the normal serviceability and bearing capacity effect of the reinforced plate beam, gave the systematical analysis of stress mechanism and failure process of prestressed concrete plate beam bridge and put forward the reinforcement pattern and calculation method of presstressed concrete plate beam. The research results of project can provide scientific basis and theoretical support for the reinforcement design theory, construction control decision and maintenance management of prestressed concrete plate beam, which has important theoretical significance and engineering value.

桥梁作为公路交通系统的咽喉工程，在国民经济和人民生活中发挥着重要作用。预应力混凝土板梁桥是现役桥梁中数量最多的桥型之一，由于设计、施工质量、材料老化、荷载等级提高及维修养护的不重视，导致桥梁结构不能满足正常使用或承载能力的要求，需要进行加固。本项目基于提高板梁的刚度、延性及承载能力等性能出发，开展超强高韧性树脂混凝土钢（铁）丝网混凝土及预应力板梁桥加固设计研究工作具有十分重要的意义。围绕新材料及加固这一前沿热门课题，采用材料试验、理论分析及室内足尺静载试验验证，综合评价梁板加固后正常使用及承载能力的效果，系统分析预应力混凝土梁板加固后受力机理及破坏过程，提出该预应力混凝土板梁加固方式的计算分析方法。本项目研究成果可为预应力梁板加固设计理论、施工控制决策和营运养护管理提供科学依据和理论支撑，具有重要的理论意义和工程应用价值。

本项目提出了超强高韧性树脂钢丝网混凝土加固预应力板桥梁这一研究内容，并系统开展了树脂混凝土增韧试验研究、树脂混凝土与钢丝网的本构关系研究、模型分析及界面粘结效果研究、超强高韧性树脂钢丝网混凝土加固对空心梁板延性及刚度影响的试验研究、超强高韧性树脂钢丝网混凝土加固对空心梁板承载能力影响的试验研究。主要研究结论有：根据正交试验确定超强高韧性树脂混凝土基材的三组份最佳配合比及最佳配合比情况下各力学参数；通过足尺梁静载试验，测试其相关参数，真实地掌握了梁体的受力全过程，同时也反映了使用HTRCS加固足尺预应力空心板的加固效果，从而为该类空心板梁加固后极限承载能力评估等提供试验依据；得出开裂荷载及不同破坏模式对应的荷载，为后期加固梁对比提供参考依据；通过试验全过程分析，总结出梁体开裂荷载及破坏荷载(承载能力)有提高，但提高不显著；通过试验数据分析得出，正常使用阶段挠度降低了13.08%，进入塑性阶段后挠度平均降低了29.07%，此加固方法在正常荷载水平上，梁体刚度提高10%左右；随着荷载的增加，进入塑性阶段后，挠度平均降低较大。上述研究内容不仅丰富了桥梁加固领域的加固方法，更完善了预应力桥梁加固的理论研究工作，具有一定的前瞻性和国内外先进性。