预应力钢板抗剪加固技术—栓接钢板极限抗剪性能试验研究

发布时间：2018-10-20 07:31

【摘要】：主动加固技术作为加固类型之一,相对被动加固技术可以明显的改善桥梁的受力状态和承载力,充分发挥加固材料的力学性能。预应力栓接钢板抗剪加固属于主动加固技术范畴,除了具有主动加固的优点外,还具有:锚固措施可靠、施工成本低、操作简便、适用性广等优点。因此,对这种新的加固方法展开研究具有十分重要的意义。目前,尚没有发现相关文献对这种加固方法展开研究。对混凝土梁进行加固时,不合理的预应力水平会造成加固效果不佳甚至可能对桥梁原有的结构造成损伤。为此,在进行混凝土梁主动抗剪加固试验研究前,有必要先进行栓接钢板极限抗剪性能的研究,确定加固时合理的预应力水平。本文通过混凝土构件试验和数值模拟两条技术路线对栓接钢板极限抗剪性能展开了研究。本文主要的研究内容和成果有:(1)、构件主动抗剪加固试验:在混凝土构件上模拟实桥加固,以锚栓直径和混凝土强度为重点研究对象,进行了27次预应力栓接钢板抗剪加固构件试验。观察了不同影响因素下各个部件的变形和破坏形态;绘制了加载全过程中钢板与混凝土的相对荷载-位移曲线;分析了不同混凝土强度和锚栓直径对加固效果的影响规律。(2)、有限元分析:运用有限元软件ABAQUS对构件主动抗剪加固试验进行了数值分析。数值结果与试验结果相吻合,真实模拟了加固时的受力机理。通过数值结果和试验结果的对比分析,得出了一些有意义的结论。(3)、理论分析与结论:在试验结果和有限元分析的基础上,对加固时的极限承载力进行了理论分析,结合不同规范的推荐公式,并依据不同破坏模式下的试验结果给出了主动抗剪加固时预应力标准值和设计值的建议公式。该公式实用性强,计算简便。最后对一座钢筋混凝土T梁桥进行了加固设计,运用修正后的公式计算了加固后的应力状态。计算结果表明,加固后桥梁斜截面的受力状态得到了明显的改善。
[Abstract]:As one of the types of reinforcement, the active reinforcement technology can obviously improve the stress state and bearing capacity of the bridge, and give full play to the mechanical properties of the strengthening materials. Shear strengthening of prestressed bolted steel plate belongs to active reinforcement technology. In addition to the advantages of active reinforcement, it also has the advantages of reliable anchoring measures, low construction cost, simple operation and wide applicability. Therefore, it is of great significance to study this new reinforcement method. At present, there is no research on this reinforcement method. When the concrete beam is strengthened, the unreasonable prestress level will result in poor reinforcement effect and may even cause damage to the original structure of the bridge. For this reason, it is necessary to study the ultimate shear resistance of the steel plate in order to determine the reasonable prestress level before carrying out the experimental study on the active shear resistance of concrete beams. In this paper, the ultimate shear resistance of steel plate is studied by means of concrete member test and numerical simulation. The main research contents and results of this paper are as follows: (1) the active shear strengthening test of the members: the concrete members are simulated to strengthen the bridge, with the Anchorage diameter and the concrete strength as the main research object. In this paper, 27 tests on shear-resistant members of prestressed bolted steel plate were carried out. The deformation and failure patterns of each component under different influence factors were observed, and the relative load-displacement curves of steel plate and concrete during the whole loading process were plotted. The influence of different concrete strength and anchor bolt diameter on the reinforcement effect is analyzed. (2) finite element analysis: using the finite element software ABAQUS, the active shear strengthening test of members is analyzed numerically. The numerical results are in agreement with the experimental results, and the stress mechanism of the reinforcement is simulated. Through the comparison and analysis of numerical and experimental results, some meaningful conclusions are drawn. (3) theoretical analysis and conclusion: on the basis of experimental results and finite element analysis, the ultimate bearing capacity of reinforcement is theoretically analyzed. Combining with the recommended formulas of different codes and according to the test results of different failure modes, the suggested formulas for the standard values and design values of prestressing force in active shear strengthening are given. The formula is practical and easy to calculate. Finally, a reinforced concrete T-beam bridge is designed and the stress state is calculated by using the modified formula. The calculated results show that the stress state of the inclined section of the strengthened bridge is obviously improved.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U446;U445.72

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