外文翻譯--預(yù)應(yīng)力混凝土斜拉橋拆除合龍段安全性分析（原文）

1、Procedia Engineering 31 (2012) 464 – 4731877-7058 © 2011 Published by Elsevier Ltd. doi:10.1016/j.proeng.2012.01.1053Available online at www.sciencedirect.comInternational Conference on Advances in Computational Mod

2、eling and Simulation Analysis on Safety of Removing the Closure Segment in a Prestressed Concrete Cable-stayed Bridge Hong-jiang Lia*, Wan-heng Lia, Jin-quan Zhanga aResearch Institute of Highway of M.O.C., Beijing 1000

3、88, China Abstract Aiming at failure of closure segment in a prestressed concrete cable-stayed bridge, a strengthening technology, namely replacing the closure segment, was firstly put forward. But removing the old clos

4、ure segment was a process of release of internal force and had great risk. So the structural safety possibly induced by removing must be analyzed and confirmed. Based on FEM and summary of engineering experience, the c

5、onstruction stages for removing the old closure segment were simulated, and then some analysis relevant to safety, including thermal effect, dynamic characteristics and global stability of the whole bridge structure, w

6、ere systematically presented. According to these analysis results, corresponding prevention and control measures were provided to ensure construction safety. Studies showed that, variation range of its structural state

7、 between before and after removing is not obvious, and its dynamic characteristics changed little after removing. In addition, structural instability could not be induced by removing, but for the sake of improving con

8、struction safety reliability, necessary safety prevention and control measures were indispensable. Analysis on safety of removing the old closure segment constituted the important part of the strengthening technology o

9、f replacing the closure segment, and became the theoretical basis of removing partial structural members for existing bridges. © 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of

10、Kunming University of Science and Technology Keywords: Prestressed concrete cable-stayed bridges; Strengthening; Replacing; Removing; Safety * Corresponding author. Tel.: +86-13910552916; fax: +86-10-62079556. E-mail a

11、ddress: hj.li@rioh.cn. 第134頁 共143頁466 Hong-jiang Li et al. / Procedia Engineering 31 (2012) 464 – 473Fig.2. Typical section of main girder. Fig.3. Crack at the wet joint. 3. Construction stage analysis on removal of t

12、he closure segment Referred to the closure process in new bridges, a method for removal of the old closure segment in Yonghe Bridge was established. On the one hand, the idea of balance weight was followed, that is, som

13、e temporary weights (e.g. water tanks) were placed at bridge deck to substitute for the weight of old closure segment to maintain the load balance for its main span. On the other hand, after removing deck pavement nea

14、r the old closure segment, the old closure segment was locked by using an external stiff frame (made by section steel) to make the main girder still continuous after removal of the old closure segment. The removal cons

15、truction sequences included releasing prestressing tendons at the old closure segment, Chiselling the concrete by step, and removing steel bars and prestressing tendons [3]. Structural mechanical modes before and after

16、 removing the old closure segment were different as shown in Fig.4. Fig. 4. (a) Structural mode before removal of the closure segment; (b) Structural mode after removal of the closure segment. To analyze and predict str

17、uctural state changes induced by removal of the closure segment, a structural initial calculation model was established by original construction process of Yonghe Bridge, and then a corrected or adjusted model was obta