面向双层交通的混凝土简支箱梁横向受力性能试验研究

发布时间：2018-05-30 00:41

本文选题：双层交通 + 混凝土简支箱梁　；参考：《湖南科技大学》2014年硕士论文

【摘要】：传统的普通混凝土箱梁桥具有整体性好，抗扭刚度大，结构动力特性优越，施工方法多样等优点，特别适用于中等跨度的城市桥梁。双层交通混凝土箱梁正是在保持传统普通混凝土箱形梁应用基础上的一种创新。它通过合理改善普通混凝土箱形梁结构形式，保证必要的净空要求，取消箱内常规设置的横隔板，使其顶、底板均成为桥面系，同时在腹板上开设必要的孔洞以满足通风、采光及消防等要求，在尽可能的保留着普通混凝土箱形截面构件的优越性能的同时又能充分利用箱梁内部结构空间，从而实现双层交通。本文的主导思想主要是探索研究该种新型结构的横向受力性能，通过在模型箱梁上进行不同荷载工况作用下的横向受力性能试验，对其在弹性阶段的挠度变形、受力分配情况、顶、底板横向应变分布规律等进行试验研究，并采用大型有限元数值模拟分析软件ANSYS对实际的试验过程进行数值模拟分析，然后对有限元数值模拟分析结果和试验结果加以分析对比，最终得到一些对双层交通混凝土箱梁有意义的结论，从而为该实现双层交通的新型混凝土结构体系的设计以及实际应用提供了参考依据。取得的主要研究成果如下： 1、荷载工况分上下加载在一道加劲环上时，跨中加劲环截面（4-4截面）的挠度值最大相差5%，开孔截面（3-3截面）的挠度值最大相差达到23%。荷载工况分上下加载在两道加劲环上时，跨中加劲环截面（4-4截面）的挠度值最大相差7%，开孔截面（3-3截面）的挠度值最大相差12%。说明截面横向加劲环的设置有效的提高了截面刚度，从而提高了梁的整体性，能有效减小荷载作用位置对模型箱梁整体挠度变形的影响。 2、在四种不同的荷载工况作用下，当荷载工况作用在底板时的箱梁挠度变形相比荷载工况作用在顶板时要大，其中以工况三即简支梁跨中加劲环底板两点对称集中加载的挠度变形最大。 3、由于箱梁腹板大面积开孔，造成截面刚度被削弱，在工况一和工况三作用下，模型梁的纵向挠度变化曲线在2m处和6m处出现曲率突变现象。建议通过减小腹板开孔尺寸或增加截面加劲环数量的措施来提高箱梁截面刚度，，从而提高整体性。 4、该箱梁模型在五种不同荷载工况作用下，顶板的#1~#4号梁共分配了40%左右的荷载，底板的#5~#8号梁共分配了60%左右的荷载。 5、当荷载作用在4-4截面即跨中加劲环截面的顶板时，即工况一加载，4-4截面即跨中截面的顶板和底板的横向应变分布规律基本一致，所测得的应变值大小也十分接近，最大值相差5%。当荷载作用在4-4截面即跨中加劲环截面的底板时，即工况三加载，顶板的横向应变值相比底板明显减小。且顶板与边腹板交界处产生的横向拉应力要明显大于与中间腹板交界处产生的横向拉应力。 6、当荷载作用在箱梁开孔段的截面顶板时，即工况二加载，由于腹板开孔影响内力的传递，导致中室的顶板出现拉应力增大的现象。
[Abstract]:The traditional concrete box girder bridge has the advantages of good integrity, large torsion stiffness, superior dynamic characteristics and various construction methods. It is especially suitable for medium span urban bridges. The double deck concrete box girder is a kind of innovation on the basis of maintaining the traditional concrete box girder. The structure form of the concrete box girder ensures the necessary clearance requirements and cancels the conventional diaphragms in the box so that the top and the bottom plate are all the bridge deck system, and the necessary holes are opened on the web to meet the requirements of ventilation, lighting and fire protection, while the superior performance of the common concrete box section members can be retained as far as possible and can be filled at the same time. The main idea of this paper is to explore the lateral force performance of the new structure. Through the test of lateral force performance under different load conditions on the model box girder, the deflection and deformation, the load distribution, the top and the horizontal side of the floor are carried out in the elastic stage. The strain distribution law is studied, and the large finite element numerical simulation analysis software ANSYS is used to carry out numerical simulation analysis on the actual test process. Then, the numerical simulation analysis results and the experimental results are analyzed and compared. Finally, some conclusions are obtained for the double deck concrete box girder. The main achievements of the study are as follows:
1, the maximum deflection value of the cross section (4-4 section) is 5%, the maximum difference of deflection value of the cross section (3-3 section) of the open hole section (3-3 section) reaches the two stiffening ring of the 23%. load, and the maximum difference of the deflection value of the cross section (4-4 section) is 7%, and the opening section (3-3). The maximum difference of deflection value 12%. shows that the setting of cross section of cross section effectively improves the stiffness of cross section, thus improves the integrity of the beam, and can effectively reduce the effect of load position on the overall deflection and deformation of the model box girder.
2, under the action of four different load conditions, the deflection and deformation of the box girder when the loading condition is acting on the floor is larger than the loading condition, and the maximum deflection and deformation of the two point symmetrical concentrated load of the bottom plate of the simple supported beam is three.
3, because of the large area opening of the box girder web, the stiffness of the section is weakened. The curvature change of the longitudinal deflection curve of the model beam appears at 2m and 6m under the condition of working condition and working condition. It is suggested that the rigidity of the section of the box girder is improved by reducing the size of the opening of the web or increasing the number of the stiffening ring of the section, thus improving the integrity.
4, under the action of five different load conditions, the box beam model #1~#4 beam of the roof is distributed about 40% load, and the #5~#8 beam of the floor is assigned a total of about 60% load.
5, when the load is loaded on the top plate of the cross section of the 4-4 cross section, that is, the load of the working condition is loaded, the transverse strain distribution of the top plate and the bottom plate of the 4-4 cross section is basically the same, and the measured strain value is very close, the maximum difference is 5%. when the load is on the floor of the 4-4 cross section of the stiffening ring section. With three loading, the lateral strain of the roof decreases obviously compared with the bottom plate, and the transverse tensile stress at the junction of the top plate and the edge web is obviously larger than the transverse tensile stress produced at the junction of the middle web.
6, when the load is acted on the section roof of the opening section of the box beam, that is, the loading of the working condition two, as the open hole of the web affects the transmission of the internal force, the tension of the roof of the middle room is increased.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.213

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