空心板梁桥横向预应力效应分析及加固设计
发布时间：2019-06-10 13:19
【摘要】：装配式空心板梁桥具有施工速度快、造价低等优点,是中国、美国、日本等国中小跨径桥梁的主要桥型之一。随着服役时间的增长,国内空心板梁桥普遍出现铰缝混凝土开裂的病害,导致横向连接能力降低,最终造成单板受力的情况,威胁桥梁的结构和行车安全。针对存在单板受力病害的空心板梁桥,基于摩擦抗剪原理,本文提出了在梁高中心位置设置横向预应力的加固方法,以恢复开裂混凝土铰缝的剪力传递能力,进而改善空心板梁桥的横向分布,达到加固目的。基于数值试验,本文的主要研究内容如下:首先,利用有限元软件ANSYS建立空心板梁桥的有限元模型,以接触单元模拟铰缝混凝土的开裂面,计算分析荷载作用下横向预应力、板间摩擦系数、板梁竖向挠度三者之间的相互关系。同时,给出空心板梁桥铰缝在不同受压高度时的横向分布影响线,并与铰接板法计算结果和铰缝完好时的有限元计算结果进行对比分析。其次,以双孔空心板梁为代表,详细分析了横向预应力作用下,接触单元的应力分布规律,探讨桥宽、桥长、预应力束数和大小、车辆荷载对铰缝应力分布规律的影响。结果显示,梁高方向,受空心板梁空腔和恒载作用影响,铰缝压应力主要分布于铰缝顶部20 cm范围内;桥长方向,相同铰缝的受压范围基本不随预应力的增大而变化。车辆荷载作用下,当预应力足够时,开裂界面间相对滑移值趋于零,板梁处于共同受力状态。最后,以我国13 m标准跨径空心板梁桥为例,给出加固设计和计算过程。先分析预应力的有效作用范围,结合桥梁跨度确定预应力布置方式,以车辆荷载作用下接触单元的最大相对滑移值为控制目标,确定横向预应力数值。并从加固后的空心板梁桥横向分布和单点加载两方面检验加固方案的可靠性,结果表明加固后的空心板梁桥横向分布规律与铰接板法计算结果吻合较好。
[Abstract]:The assembled hollow slab beam bridge has the advantages of fast construction speed and low cost. It is one of the main bridge types of small and medium-sized span bridges in China, the United States, Japan and other countries. With the increase of service time, the cracking disease of joint concrete generally occurs in hollow slab beam bridges in China, which leads to the decrease of transverse connection capacity, and finally leads to the stress of veneer, which threatens the structure and driving safety of bridges. Aiming at the hollow slab beam bridge with veneer stress disease, based on the friction shear principle, this paper puts forward a reinforcement method of setting transverse prestress at the center of beam height in order to restore the shear transfer capacity of cracked concrete joint. Then the transverse distribution of hollow slab beam bridge is improved to achieve the purpose of reinforcement. Based on numerical experiments, the main research contents of this paper are as follows: firstly, the finite element model of hollow slab beam bridge is established by using finite element software ANSYS, the crack surface of joint concrete is simulated by contact element, and the transverse prestress under load is calculated and analyzed. The relationship between friction coefficient between plates and vertical deflection of plates and beams. At the same time, the transverse distribution influence lines of hollow slab beam bridge joints at different compression heights are given, and the results are compared with those of the joint method and the finite element method when the joints are in good condition. Secondly, taking the double hole hollow slab beam as the representative, the stress distribution law of the contact element under the action of transverse prestress is analyzed in detail, and the influence of bridge width, bridge length, number and size of prestressed beam and vehicle load on the stress distribution law of the joint is discussed. The results show that the compressive stress of the joint is mainly distributed in the range of 20 cm at the top of the joint under the influence of cavity and dead load in the direction of beam height, and the compression range of the same joint does not change with the increase of prestress in the long direction of the bridge. Under the action of vehicle load, when the prestress is enough, the relative slip value between the cracking interfaces tends to zero, and the plate beam is in the common stress state. Finally, taking the 13 m standard span hollow slab beam bridge in China as an example, the reinforcement design and calculation process are given. Firstly, the effective action range of prestress is analyzed, and the prestress arrangement mode is determined according to the bridge span. The maximum relative slip value of contact element under vehicle load is taken as the control goal, and the transverse prestress value is determined. The reliability of the reinforcement scheme is tested from two aspects of transverse distribution and single point loading of the strengthened hollow slab beam bridge. The results show that the transverse distribution law of the strengthened hollow slab beam bridge is in good agreement with the calculation results of the bonded plate method.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.72
，
本文编号：2496480
[Abstract]:The assembled hollow slab beam bridge has the advantages of fast construction speed and low cost. It is one of the main bridge types of small and medium-sized span bridges in China, the United States, Japan and other countries. With the increase of service time, the cracking disease of joint concrete generally occurs in hollow slab beam bridges in China, which leads to the decrease of transverse connection capacity, and finally leads to the stress of veneer, which threatens the structure and driving safety of bridges. Aiming at the hollow slab beam bridge with veneer stress disease, based on the friction shear principle, this paper puts forward a reinforcement method of setting transverse prestress at the center of beam height in order to restore the shear transfer capacity of cracked concrete joint. Then the transverse distribution of hollow slab beam bridge is improved to achieve the purpose of reinforcement. Based on numerical experiments, the main research contents of this paper are as follows: firstly, the finite element model of hollow slab beam bridge is established by using finite element software ANSYS, the crack surface of joint concrete is simulated by contact element, and the transverse prestress under load is calculated and analyzed. The relationship between friction coefficient between plates and vertical deflection of plates and beams. At the same time, the transverse distribution influence lines of hollow slab beam bridge joints at different compression heights are given, and the results are compared with those of the joint method and the finite element method when the joints are in good condition. Secondly, taking the double hole hollow slab beam as the representative, the stress distribution law of the contact element under the action of transverse prestress is analyzed in detail, and the influence of bridge width, bridge length, number and size of prestressed beam and vehicle load on the stress distribution law of the joint is discussed. The results show that the compressive stress of the joint is mainly distributed in the range of 20 cm at the top of the joint under the influence of cavity and dead load in the direction of beam height, and the compression range of the same joint does not change with the increase of prestress in the long direction of the bridge. Under the action of vehicle load, when the prestress is enough, the relative slip value between the cracking interfaces tends to zero, and the plate beam is in the common stress state. Finally, taking the 13 m standard span hollow slab beam bridge in China as an example, the reinforcement design and calculation process are given. Firstly, the effective action range of prestress is analyzed, and the prestress arrangement mode is determined according to the bridge span. The maximum relative slip value of contact element under vehicle load is taken as the control goal, and the transverse prestress value is determined. The reliability of the reinforcement scheme is tested from two aspects of transverse distribution and single point loading of the strengthened hollow slab beam bridge. The results show that the transverse distribution law of the strengthened hollow slab beam bridge is in good agreement with the calculation results of the bonded plate method.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.72
，
本文编号：2496480
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