桥梁纠偏技术及其应用

发布时间：2018-04-10 01:37

本文选题：桥梁工程　切入点：偏位成因分析　出处：《长安大学》2015年硕士论文

【摘要】：论文针对中、小跨径桥梁中普遍存在而又极易被人忽视的桥梁偏位问题展开研究。首先对桥梁在各种内外因素下发生纵、横向偏位现象进行了归类,并在此基础上采用数值方法完成了病害成因的验证分析。其次,以依托工程为例,对桥梁偏位及纠偏施工的全过程进行仿真分析。最后提出了合理的纠偏施工和监测方案,并通过现场纠偏实施验证了研究成果的合理性。论文通过以上系统的研究,得出以下结论:(1)引起桥梁偏位的因素主要分为内因和外因两种,其中内因有桥梁平面曲率、支座布置、收缩徐变等;外因有温度作用、车辆荷载、伸缩缝堵塞和卡死、支座不均匀沉降等。(2)温度作用是引起梁体偏移的主要原因,尤其是曲线梁桥更为突出。其次活载作用的影响也不容忽视。在排除偶然事件(如地震、车船撞击等)的影响,温度作用一项引起的偏移量往往大于其他所有因素的总和。(3)曲率半径也是造成梁体偏移的主要原因之一。随着曲率半径的减小,其对横向偏位的影响逐渐增大,对纵向偏位的影响逐渐减小,因此,当曲率半径较小时,以横向偏位研究为主;当曲率半径较大时,以纵向偏位研究为主。(4)由于伸缩缝的卡死或堵塞,使得梁体的升降温边界条件不同(卡死或堵塞限制了梁的伸长但没有限制缩短),会引起梁在温度作用下的“爬行”,使偏移量大幅增加,此问题在曲线梁桥尤为突出。(5)支座设置形式对梁体的偏移量影响显著。文中对两组、四种具有代表性的支座分布形式进行了分析。分析发现,对于弯桥选择中间固定,其余采用纵向活动、横向约束的支座形式对梁体的偏位预防效果最好。(6)多梁式桥梁的顶升过程受力非常复杂,建议应在施工时对顶升断面的应力变化进行重点监测。此外,为了降低顶升断面的应力峰值,顶升时也应将相邻支点顶升一定高度。(7)弯桥一联中桥跨过多(结构单元过长)也会影响到偏移量的变化(偏移量会增大),尤其对两端纵向偏位的影响较大。
[Abstract]:In this paper, the problem of bridge deflection, which is common in small span bridges and is easy to be neglected, is studied in this paper.In this paper, the longitudinal and transverse deflection of the bridge is classified under various internal and external factors, and based on this, the cause of the disease is verified and analyzed by numerical method.Secondly, the whole process of bridge deflection and rectifying construction is simulated and analyzed by taking the supporting project as an example.Finally, a reasonable scheme of rectifying construction and monitoring is put forward, and the rationality of the research result is verified by the implementation of correction on the spot.Based on the above systematic research, the following conclusions are drawn: (1) the main causes of bridge deflection are internal and external factors, including plane curvature of bridge, support arrangement, shrinkage and creep, external factors, temperature, vehicle load, and so on, and the following conclusions can be obtained: (1) the main causes of bridge deflection are internal and external factors, such as plane curvature of bridge, support arrangement, shrinkage and creep, etc.The effect of temperature on the blockage and clamping of expansion joints, uneven settlement of supports, etc.) is the main cause of beam body deviation, especially the curved girder bridge is more prominent.Secondly, the influence of live load can not be ignored.When excluding the influence of accidental events (such as earthquakes, vehicle-ship impacts, etc.), the curvature radius caused by one term of temperature action is often larger than the sum of all other factors. The curvature radius is also one of the main causes of beam migration.With the decrease of curvature radius, the influence on transverse deviation increases gradually, and the influence on longitudinal deviation decreases gradually. Therefore, when the curvature radius is small, the study of transverse deviation is the main one, and when the curvature radius is large,Due to the clamping or blockage of the expansion joints, the boundary conditions for the rise and cooling of the beam body are different (the clamping or blockage limits the elongation of the beam but does not limit the shortening of the beam, which will lead to the "creep" of the beam under the action of temperature.The offset is greatly increased, especially in curved girder bridge. This problem has a significant effect on the deflection of beam body.In this paper, two groups, four representative support distribution forms are analyzed.It is found that, for the curved bridge with intermediate fixation, the rest with longitudinal movement and transverse constraint supports have the best preventive effect on the deflection of beam body, and the uplift process of multi-beam bridge is very complicated.It is suggested that stress change of uplift section should be monitored emphatically during construction.In addition, in order to reduce the peak stress of the uplift section,When lifting, the adjacent fulcrum should be lifted up to a certain height.) too much span (too long structural unit) in the bridge with curved bridge will also affect the change of the offset (the offset will increase, especially the influence on the longitudinal deviation of the two ends is greater.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.7

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