某预应力混凝土连续梁桥落架方案分析
发布时间：2018-07-21 15:18
【摘要】：满堂支架法是一种在客运专线和城市桥梁建设中运用十分广泛的施工方法,但专门针对支架拆除方面的研究较少。本文以某铁路预应力混凝土连续梁桥为工程背景,该桥沿大里程方向地势由高到低,原施工方案中,施工方计划在地势高的边跨下直接制作土模,其他两跨搭设满堂支架。一般的支架拆除的方法显然无法适用于本文中的情况,为了验证该落架方案的安全性,本文主要工作包含以下几个方面内容:(1)在工地实习过程中,收集文中连续梁桥施工图纸、施工组织文件,详细了解该连续梁桥的落架方案及施工要点,并归纳了拆架过程中可能会出现的4种极端工况。(2)通过查找规范及阅读大量相关文献,总结影响落架方案安全性的相关指标。(3)根据施工图纸,选用MIDAS/Civil梁格建模助手建立了该3×32m连续梁模型,其中选用梁单元来模拟箱梁,用等效荷载法来模拟预应力筋的作用,用节点弹性支承来模拟土模和支架的作用。(4)通过改变模型边界条件的方法来模拟各种工况,得出各工况下梁体的应力、挠度和支座反力,对计算结果进行整理、比较和分析,并与规范要求进行比较,针对最不利工况,提出有针对性的应对措施和预防方法。通过结果分析得到如下几个主要结论:(1)采用土模的边跨(左边跨)横向的不均匀落架,会引起左边跨跨中区域上缘出现较大的主拉应力,且桥台1支座处的反力会发生重分布,拆除与未拆除土模部分的支座反力差值较大,这可能会造成支座与梁体分离;同时还会引起左边跨出现较大的上挠。因此建议拆除左边跨土模时,一定要安排专人盯控,务必使两侧拆除土模保持一致。(2)如果不移除土模,同时拆除右边跨和中跨比仅拆除中跨产生的压应力要小。依此规律拆除支架时可遵循先落中跨后落边跨的规律。(3)只要左边跨横向对称拆除土模,不同工况下全桥均为受压状态,符合安全要求。若仍采用原施工方案,推荐中跨和右边跨先落架,左边跨土模采用横向对称均匀落架。针对未落架桥跨的上挠,可以在落架前采用临时堆载的方式降低其上挠。
[Abstract]:Full-hall support method is a widely used construction method in the construction of passenger dedicated lines and urban bridges. In this paper, a railway prestressed concrete continuous beam bridge is used as the engineering background. The bridge moves from high to low along the direction of long mileage. In the original construction plan, the construction side plans to make soil mold directly under the high side span of the terrain, and the other two spans to set up the full hall support. In order to verify the safety of this scheme, the main work of this paper includes the following aspects: (1) in the process of site practice, the construction drawings of continuous beam bridges are collected. Construction organization documents, detailed understanding of the continuous beam bridge fall scheme and construction points, and summed up the process of demolition of the four extreme conditions. (2) by looking up the norms and reading a large number of related documents, The related indexes affecting the safety of the falling frame scheme are summarized. (3) according to the construction drawings, the 3 脳 32m continuous beam model is established by Midas / Civil grid modeling assistant, in which the beam element is used to simulate the box girder, and the effect of prestressed tendons is simulated by the equivalent load method. (4) by changing the boundary conditions of the model to simulate the various working conditions, the stress, deflection and support reaction force of the beam under each working condition are obtained, and the calculated results are sorted out, compared and analyzed, by using the elastic support of the joint to simulate the action of the soil mold and the support. (4) by changing the boundary conditions of the model, the stress, deflection and support reaction force of the beam are obtained. Compared with the standard requirements, the paper puts forward some countermeasures and prevention methods for the most disadvantageous working conditions. The main conclusions are as follows: (1) the lateral uneven falling frame of the side span (left span) of the soil model will cause the larger main tensile stress on the upper edge of the left span, and the reaction force at the support 1 of abutment 1 will be redistributed. The difference of the support force between the removed and unremoved soil mold parts is larger, which may result in the separation of the support from the beam body, and at the same time, it will cause a large upper deflection in the left span. Therefore, it is suggested that when removing the left cross soil mold, special personnel must be arranged to watch and control it. (2) if the soil mold is not removed at the same time, the compression stress generated by removing the right span and the middle span should be smaller than that of only the middle span. According to this rule, the support can be removed according to the rule of first falling middle span and then falling edge span. (3) as long as the left side span is symmetrical to remove the soil mold, the whole bridge is under pressure under different working conditions, which conforms to the safety requirements. If the original construction scheme is still adopted, it is recommended that the middle span and the right span fall first, and the left cross soil model adopt transverse symmetrical uniform fall frame. In view of the deflection of the unfallen bridge span, the temporary surcharge can be used to reduce the upwarping deflection before the fall.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.4
本文编号：2135943
[Abstract]:Full-hall support method is a widely used construction method in the construction of passenger dedicated lines and urban bridges. In this paper, a railway prestressed concrete continuous beam bridge is used as the engineering background. The bridge moves from high to low along the direction of long mileage. In the original construction plan, the construction side plans to make soil mold directly under the high side span of the terrain, and the other two spans to set up the full hall support. In order to verify the safety of this scheme, the main work of this paper includes the following aspects: (1) in the process of site practice, the construction drawings of continuous beam bridges are collected. Construction organization documents, detailed understanding of the continuous beam bridge fall scheme and construction points, and summed up the process of demolition of the four extreme conditions. (2) by looking up the norms and reading a large number of related documents, The related indexes affecting the safety of the falling frame scheme are summarized. (3) according to the construction drawings, the 3 脳 32m continuous beam model is established by Midas / Civil grid modeling assistant, in which the beam element is used to simulate the box girder, and the effect of prestressed tendons is simulated by the equivalent load method. (4) by changing the boundary conditions of the model to simulate the various working conditions, the stress, deflection and support reaction force of the beam under each working condition are obtained, and the calculated results are sorted out, compared and analyzed, by using the elastic support of the joint to simulate the action of the soil mold and the support. (4) by changing the boundary conditions of the model, the stress, deflection and support reaction force of the beam are obtained. Compared with the standard requirements, the paper puts forward some countermeasures and prevention methods for the most disadvantageous working conditions. The main conclusions are as follows: (1) the lateral uneven falling frame of the side span (left span) of the soil model will cause the larger main tensile stress on the upper edge of the left span, and the reaction force at the support 1 of abutment 1 will be redistributed. The difference of the support force between the removed and unremoved soil mold parts is larger, which may result in the separation of the support from the beam body, and at the same time, it will cause a large upper deflection in the left span. Therefore, it is suggested that when removing the left cross soil mold, special personnel must be arranged to watch and control it. (2) if the soil mold is not removed at the same time, the compression stress generated by removing the right span and the middle span should be smaller than that of only the middle span. According to this rule, the support can be removed according to the rule of first falling middle span and then falling edge span. (3) as long as the left side span is symmetrical to remove the soil mold, the whole bridge is under pressure under different working conditions, which conforms to the safety requirements. If the original construction scheme is still adopted, it is recommended that the middle span and the right span fall first, and the left cross soil model adopt transverse symmetrical uniform fall frame. In view of the deflection of the unfallen bridge span, the temporary surcharge can be used to reduce the upwarping deflection before the fall.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.4
【参考文献】
相关期刊论文 前10条
1 侯鹏飞;叶文启;赵元一;贺先德;;环形天桥落架施工的数值模拟及其应用[J];工业建筑;2016年07期
2 唐忠林;宋晓东;;大跨度多塔斜拉桥边跨落架研究[J];四川建筑科学研究;2016年02期
3 柴文龙;;满堂支架法支架搭设与受力计算[J];城市道桥与防洪;2014年03期
4 刘新华;;结合工程实例谈满堂支架法现浇连续梁施工[J];价值工程;2013年04期
5 牛瑞军;;浅谈桥梁工程中箱梁满堂支架的施工技术[J];科技信息;2011年25期
6 阙名前;;跨既有高速公路桥梁施工支架拆除方案[J];山西建筑;2011年05期
7 李文斌;雷坚强;曾德荣;;移动贝雷梁柱支架空间稳定性研究[J];重庆交通大学学报(自然科学版);2009年01期
8 李杨;;客运专线移动模架法箱梁预制施工技术[J];铁道建筑;2008年10期
9 刘晓平;;满堂支架现浇连续箱梁的质量控制[J];黑龙江交通科技;2008年06期
10 陈恒山;吴静;陈湘林;;顶推法施工在桥梁工程中的应用[J];中外公路;2006年03期
相关会议论文 前1条
1 黎雷;;钢箱梁顶推施工[A];中国公路学会桥梁和结构工程学会2002年全国桥梁学术会议论文集[C];2002年
相关硕士学位论文 前10条
1 史战萍;桥梁满堂支架节点力学性能研究[D];贵州大学;2016年
2 项嫣姝;市域铁路简支箱梁支架现浇技术研究[D];浙江工业大学;2016年
3 杨兴华;顶推法施工自锚式悬索桥关键技术与控制[D];沈阳建筑大学;2015年
4 孔君;大跨度预应力混凝土连续梁桥施工监控[D];北京交通大学;2014年
5 李明哲;基于施工风险评估的桥梁工程保险费率厘定优化研究[D];长安大学;2014年
6 孙艳武;连续梁桥悬臂法施工控制及合拢次序研究[D];河北工业大学;2012年
7 王鹤;下坞蓟运河特大桥7跨连续梁顶推施工技术研究[D];中南大学;2012年
8 李浩;支架现浇预应力混凝土连续箱梁桥施工控制技术[D];长安大学;2011年
9 吴秋良;山地城市现浇箱梁满堂支架关键施工技术[D];重庆交通大学;2011年
10 陈永瑞;碗扣式模板支撑架设计及施工监控[D];长安大学;2011年
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