复合砂浆预应力钢丝绳抗弯加固的研究

发布时间：2018-04-07 17:28

本文选题：复合砂浆　切入点：钢丝绳　出处：《东北林业大学》2014年硕士论文

【摘要】：桥梁长期在自然环境和使用环境的荷载作用下,常出现损伤与病害,承载能力下降,严重影响到桥梁的正常使用。对大量既有桥梁进行维修、加固与改造,保持其正常使用功能,延长其使用寿命,具有重要的工程价值和意义。复合砂浆预应力钢丝绳加固技术是一种新型的加固技术采用小直径预应力钢丝绳作为预应力的施加介质,通过锚具传递到加固结构上,并用复合砂浆对钢丝绳进行防护的方法提高旧桥承载能力。它有着显著的优点：小直径钢丝绳锚固较容易,而且强度高可以可靠传递预应力；复合砂浆可以将钢丝绳与梁体可靠的粘结到一起,具有锚固及防止预应力筋锈蚀的作用,延长了加固体系的耐久性；预应力的施加引起桥梁一定程度的反拱,减小了由自重引起的内力,极大地提高了桥梁的安全性能。本文首先对采用复合砂浆预应力钢丝绳加固的钢筋混凝土矩形梁进行了抗弯性能试验研究,试验包括1根对比梁和4根加固梁,分析了钢丝绳的不同布置方式以及复合砂浆对梁体抗弯性能的影响,并利用ANSYS有限元分析软件对钢丝绳加固梁和未加固梁的试验过程进行了非线性数值模拟,将有限元模型分析结果与试验结果进行对比,以验证试验结果的可靠性,同时进行了抗弯加固的有限元参数分析,着重分析了混凝土强度及钢丝绳的张拉控制应力大小对加固构件开裂荷载和屈服荷载的影响,最后用复合砂浆预应力钢丝绳加固方法对实际加固工程桥梁进行加固设计,通过对加固前后的挠度、应变等数据的对比分析,预应力钢丝绳加固方法可以明显提高旧桥的承载能力,较大程度改善原桥的受力性能,对桥梁结构的受力裂缝有较好的收缩作用,而复合砂浆则可延长预应力钢丝绳的使用寿命,具有较好的耐久性能。
[Abstract]:Under the load of natural environment and service environment for a long time, the bridge often appears damage and disease, and the bearing capacity decreases, which seriously affects the normal use of the bridge.It is of great engineering value and significance to repair, reinforce and rebuild a large number of existing bridges, to maintain their normal function and to prolong their service life.The composite mortar prestressed wire rope reinforcement technology is a new type of reinforcement technology. The small diameter prestressed wire rope is used as the applied medium of the prestressing force, which is transferred to the strengthened structure through the anchor.The bearing capacity of old bridge is improved by using composite mortar to protect wire rope.It has obvious advantages: small diameter wire rope anchoring is easy, and high strength can reliably transfer prestress; composite mortar can bond the wire rope to beam body reliably, which has the function of anchoring and preventing the corrosion of prestressed tendons.The durability of the reinforcement system is prolonged, and the application of prestress causes a certain degree of reverse arch of the bridge, reduces the internal force caused by self-weight, and greatly improves the safety performance of the bridge.In this paper, the flexural behavior of reinforced concrete rectangular beams strengthened by composite mortar prestressed steel wire rope is studied in this paper. The experiment includes one contrast beam and four strengthened beams.The different arrangement of wire rope and the influence of composite mortar on the bending behavior of beam are analyzed. The nonlinear numerical simulation of the test process of steel wire rope strengthened beam and unstrengthened beam is carried out by using ANSYS finite element analysis software.The finite element model analysis results are compared with the test results to verify the reliability of the test results, and the finite element parameter analysis of flexural reinforcement is also carried out.The influence of concrete strength and tension control stress of steel wire rope on the cracking load and yield load of reinforced members is analyzed emphatically. Finally, the reinforcement design of practical strengthened bridge is carried out by using composite mortar prestressed steel wire rope reinforcement method.Through the comparison and analysis of deflection, strain and other data before and after reinforcement, the prestressed wire rope reinforcement method can obviously improve the bearing capacity of the old bridge and greatly improve the mechanical performance of the original bridge.The composite mortar can prolong the service life of prestressed wire rope and has better durability.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.7

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