36
DOI:10.7672/sgjs2014110036
施工技术
CONSTRUCTION TECHNOLOGY
2014年6月上第43卷第11期
军扬互通立交匝道桥框架墩托换改造分析
李杰，陈淮，孙增寿
（郑州大学土木工程学院，河南郑州450001）
[摘要】采用有限元软件MIDAS/Civil建立军扬互通立交B，C匝道桥有限元计算模型，计算既有结构在不利荷载组合下的变形、内力和应力，依据B，C匝道桥4个支承传递最大支反力，采用有限元软件ALGOR建立新建框架墩实体有限元计算模型，对框架墩的变形和应力进行数值分析，参照理论分析结果对框架墩托换改造进行施工监控。分析计算结果表明，既有匝道桥支承截面顶板拉应力超限，但满足极限承载能力要求，裂缝宽度满足正常使用极限状态要求；预应力混凝土框架墩的横梁在最不利荷载组合下的变形较小，压应力储备充裕。施工监控实测数据表
明，该框架墩在施工中的变形、应力稳定，实测值与理论值较吻合。【关键词】桥梁工程；匝道桥；框架墩；托换改造；监控
［中图分类号］U443.22
【文献标识码］A
［文章编号］1002-8498(2014)11-0036-04
AnalysisofReformationandReplacementConstructionofFrame
Piers for Junyang Interchange Ramp Bridges
Li Jie,Chen Huai, Sun Zengshou
(School of Ciail Engineering, Zhengzhou Uninersity, Zhengzhou, He' nan 450001, China )
Abstract : Building finite element model of Junyang interchange B and C ramp bridge, calculating existing structural displacement, internal force and stress under unfavorable load combination, according to the maximum reaction force from B and C ramp bridge, building new frame piers block model, frame piers' displacement and stress are analyzed. According to the results of theoretical analysis, construction monitoring and control are carried out during reformation and replacement of frame piers. It is draw that existing ramp's supporting section roof tensile stress has been over the limit through analysis, but it meets the requirements of the ultimate bearing capacity and its crack width meets the requirements of the normal limit states. PC frame piers cross girder's displacement is small and compressive stress reserve is aaaeeaeoeooaooo frame piers are stable in construction, which coincides with theory results.
Key words:bridges ; ramp bridges;frame piers; reformation and replacement; monitoring
1工程概况
武西高速公路与郑州西南绕城高速公路在军
杨互通立交相对接，军杨互通立交原B币道桥B2 号和B22号墩，原C匝道桥C3号和C4号墩与新建道路冲突（见图1），为了利用既有结构，对原B匝道桥第5联和C匝道桥第1联进行改造。原B匝道桥第5联为6~20m钢筋混凝土连续梁桥，桥宽 10m，下部结构为桩柱式，共用墩为双柱，Φ1.5m桩接d1.2m柱.其余各墩为单柱，Φ1.8m桩接Φ1.4m 柱；原C匝道桥第1联为7~20m钢筋混凝土连续
[作者简介】李杰，副教授，博士，E-mail:public_li@126.com【收稿日期］2013-04-23
梁桥，桥宽8.5m，下部结构为桩柱式，共用墩及C4 号墩为双柱.Φ1.5m桩接Φ1.2m柱，其余各墩为单柱，Φ1.8m桩接Φ1.4m柱。原B匝道桥第5联B18 号和B24号墩设置双向滑动支座，B21号墩设置固定支座，其余各墩设置单向滑动支座（横桥向固定）：原C匝道桥第1联CO号墩和C7号墩设置双向滑动支座，C4号墩设置单向滑动支座（顺桥向固定），其余各墩设置单向滑动支座（横桥向固定）。其改造方案为：拆除原有下部结构，即原B匝道桥 B21号和B22号墩，原C匝道桥C3号和C4号墩，利用新建的4个框架墩代替拆除的桥墩，既有结构按照原设计规范及技术标准执行，新建结构按新规