基于静载试验的桥梁安全性研究

发布时间：2018-08-26 16:02

【摘要】：作为交通枢纽，桥梁已经成为各地区经济发展的纽带，对经济的迅速增长起着至关重要的作用。根据中国交通部对桥梁情况的统计，在我国的桥梁中有部分是危桥，并且数目呈增长趋势。如果不及时消除这些桥梁中的安全隐患，势必将造成重大的人员与经济损失。因此，部分新建和正在建设中的桥梁，面临着能否保证大桥安全运营所必要的安全性研究本文选取邢汾高速小戈廖大桥右幅3-4号有粘结预应力T梁与沙河大桥左幅33-2号有粘结预应力箱梁作为试验梁，在跨中进行3个循环的集中加载（3个加载循环的控制荷载分别为开裂状态下的荷载、正常使用极限状态下的荷载与极限承载能力状态下的荷载），且对在3个循环分级加载过程中的挠度、残余变位、应变、应力、开裂状态以及裂缝宽度进行测量与分析，从而对桥梁的安全性作出评价；借助对有粘结预应力混凝土T梁的试验，对有粘结预应力混凝土的损失进行分析；在分级加载过程中，预应力钢筋应力增量由锚具、预应力钢筋与注浆后之间的粘结力共同传递给混凝土，，对二者承担的比例进行分析研究。研究结果表明：有粘结预应力试验T梁与有粘结预应力试验箱梁在开裂状态下的抗裂性能，正常使用极限状态下的刚度、裂缝宽度以及极限承载能力状态下强度均可以满足规范的要求，即：设计的预应力混凝土T梁与预应力混凝土箱梁的安全性可以保证；《公路钢筋混凝土与预应力混凝土桥梁设计规范》（JTG D62-2004）中规定的曲线布置预应力钢筋的有粘结预应力筋预应力损失的计算公式是实际损失的1.52倍；在分级加载过程中，有粘结预应力混凝土结构预应力主要是由预应力钢筋与注浆后之间的粘结力传递给混凝土，由锚具传递给混凝土的部分可以忽略不计，在重复荷载作用下，若能保证可靠的注浆，锚具处预应力钢筋的疲劳破坏基本不可能发生。
[Abstract]:As a transportation hub, bridge has become the link of regional economic development and plays a vital role in the rapid economic growth. According to the statistics of China's Ministry of Communications, there are some dangerous bridges in our country, and the number of bridges is increasing. If the hidden dangers of these bridges are not eliminated in time, it will cause great loss of personnel and economy. As a result, some of the bridges that are being built and under construction, In the face of whether or not to ensure the safety of the bridge, this paper selects the bonded prestressed T-beam 3-4 on the right of Xingfen High-speed Xiaogoliao Bridge and the 33-2 bonded Prestressed Box girder on the left of Shahe Bridge as test beams. Three cycles of concentrated loading are carried out in the span (the control load of the three loading cycles is respectively the load under cracking condition, The deflection, residual displacement, strain, stress, crack state and crack width during three cycles of graded loading are measured and analyzed. Thus the safety of the bridge is evaluated, the loss of the bonded prestressed concrete is analyzed by means of the test of the bonded prestressed concrete T-beam, and the stress increment of the prestressed steel bar is increased by the anchor in the process of graded loading. The bond force between prestressed steel bar and grouting is transferred to concrete together, and the ratio between them is analyzed and studied. The results show that the crack resistance of the bonded prestressed test T beam and the bonded prestressed test box girder under cracking condition, and the stiffness under the limit condition of normal use are obtained. The crack width and the strength under the condition of ultimate bearing capacity can meet the requirements of the code, that is, the security of the prestressed concrete T-beam and the prestressed concrete box girder can be guaranteed; The formula for calculating the prestress loss of bonded prestressed tendons in curved arrangement of prestressed steel bars specified in the Code for Design of Highway reinforced concrete and Prestressed concrete Bridges (JTG D62-2004) is 1.52 times of the actual loss. The prestress of bonded prestressed concrete structure is mainly transferred to concrete by the bond force between prestressed steel bar and grouting, and the part transferred from anchor to concrete can be ignored, under the action of repeated load, If reliable grouting can be guaranteed, fatigue failure of prestressed steel bar at Anchorage is impossible.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U446;U447

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