-
摘要: 为了分析拓宽后桥梁的时间效应, 研究了每一时段内由混凝土收缩引起的应力的连续变化和混凝土的弹性模量变化, 根据能量原理推导了混凝土收缩徐变的位移法基本方程, 按增量法分析了徐变应变的变化, 编制了相应的计算程序。为验证理论计算的正确性, 与小试件的试验结果作了比较。在拼接缝处的受拉区, 应变计算值与实测值的相对误差为10%, 计算精度比代数法高。在新梁混凝土的收缩应力和新梁自重应力的徐变作用下, 3 a后新梁翼板的拉应力为2.67 MPa, 可能会引起混凝土开裂。为减少收缩徐变对新旧梁受力的影响, 建议新梁脱模后至少放置6个月后再进行拼接处理。Abstract: In order to analyze the long-term effect of widening for concrete T-girder bridge, the continuous change of stress resulted from the shrinkage and elastic modulus change of concrete in each period of time were studied, the basic formulas of shrinkage and creep were derived by using displacement method based on energy principle, the strain change of creep was analyzed by using incremental method, and corresponding calculation program was compiled.For testing the program, the calculation result of test pieces was compared with their measure result.Their relative error is 10% at the joint of new and old concretes, so the computation precision of the program is higher compared with algebraic method.The tensile stress at flange plate of new girder is 2.67 MPa under creep effect aroused by shrinkage stress and self-weight stress of new girder in 3 a, which may lead to concrete crack.For reducing the effect of shrinkage and creep, it is suggested that bridge should be widened after new girder is placed at least 6 months.
-
Key words:
- bridge engineering /
- bridge widening /
- energy principle /
- displacement method /
- shrinkage /
- creep
-
[1] 温庆杰, 叶见曙. 新旧钢筋混凝土梁横向拼接的收缩徐变效应分析[J]. 东南大学学报: 自然科学版, 2006, 36 (4): 596-600. doi: 10.3321/j.issn:1001-0505.2006.04.021Wen Qing-jie, Ye Jian-shu. Analysis of shrinkage and creepeffects in widening reinforced concrete girder[J]. Journal ofSoutheast University: Natural Science Edition, 2006, 36 (4): 596-600. (in Chinese) doi: 10.3321/j.issn:1001-0505.2006.04.021 [2] Echigo S, Tachibana Y, Kitaji ma A. Newtype hybrid structureand practical analysis method of creep and shrinkage[J]. Con-struction and Building Materials, 1998, 12 (2/3): 93-103. [3] 陈太聪, 苏成, 韩大建. 桥梁节段施工过程中混凝土收缩徐变效应仿真计算[J]. 中国公路学报, 2003, 16 (4): 55-58. doi: 10.3321/j.issn:1001-7372.2003.04.012Chen Tai-cong, Su Cheng, Han Da-jian. Si mulation calcula-tion of creep and shrinkage effects of concrete during segmen-tal construction of bridges[J]. China Journal of Highway andTransport, 2003, 16 (4): 55-58. (in Chinese) doi: 10.3321/j.issn:1001-7372.2003.04.012 [4] Gardner N J, Zhao J W. Creep and shrinkage revised[J]. ACI Materials Journal, 1993, 90 (3): 236-246. [5] 余报楚, 张哲, 李生勇, 等. 一种混凝土桥梁徐变的有效计算方法[J]. 哈尔滨工业大学学报, 2006, 38 (6): 994-996. doi: 10.3321/j.issn:0367-6234.2006.06.047Yu Bao-chu, Zhang Zhe, Li Sheng-yong, et al. Accuratemethod of calculating creep deformation andinternal force forconcrete bridge[J]. Journal of Harbin Institute of Technolo-gy, 2006, 38 (6): 994-996. (in Chinese) doi: 10.3321/j.issn:0367-6234.2006.06.047 [6] 张丽芳, 汪洁. 徐变计算理论及其在软件开发中的应用[J]. 西安建筑科技大学学报: 自然科学版, 2005, 37 (4): 509-513. https://www.cnki.com.cn/Article/CJFDTOTAL-XAJZ200504014.htmZhang Li-fang, Wang Jie. Creep theory and its application in software development[J]. Journal of Xi an University of Ar-chitecture and Technology: Natural Science Edition, 2005, 37 (4): 509-513. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAJZ200504014.htm [7] 范立础, 杜国华, 鲍卫刚. 桥梁结构徐变次内力分析[J]. 同济大学学报: 自然科学版, 1991, 19 (1): 23-32. https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ199101004.htmFan Li-chu, Du Guo-hua, Bao Wei-gang. Analysis of con-crete bridges for secondaryinner force of creep[J]. Journal ofTongji University: Natural Science, 1991, 19 (1): 23-32. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ199101004.htm [8] 颜东煌, 田仲初, 李学文, 等. 混凝土桥梁收缩徐变计算的有限元方法与应用[J]. 中国公路学报, 2004, 17 (2): 55-58. doi: 10.3321/j.issn:1001-7372.2004.02.012Yan Dong-huang, Tian Zhong-chu, Li Xue-wen, et al. Finiteelement method and applicationfor the shrinkage and creep ofconcrete bridges[J]. China Journal of Highway and Trans-port, 2004, 17 (2): 55-58. (in Chinese) doi: 10.3321/j.issn:1001-7372.2004.02.012 [9] Bazant Z P. Prediction of concrete creep effects using age-ad-justed effective modulus method[J]. ACI Journal, 1972, 69 (4): 212-217. [10] 王勋文, 潘家英. 按龄期调整有效模量法中老化系数x的取值问题[J]. 中国铁道科学, 1996, 17 (3): 12-23. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGTK603.001.htmWang Xun-wen, Pan Jia-ying. Evaluating aging coefficientxin age-adjusted effective modulus method[J]. China Rail wayScience, 1996, 17 (3): 12-23. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZGTK603.001.htm [11] 刘健, 赵国藩. 新老混凝土粘结收缩性能研究[J]. 大连理工大学学报, 2001, 41 (3): 339-342. doi: 10.3321/j.issn:1000-8608.2001.03.019Liu Jian, Zhao Guo-fan. Study of shrinkage performance ofadherence of young on old concrete[J]. Journal of DalianUniversity of Technology, 2001, 41 (3): 339-342. (in Chinese) doi: 10.3321/j.issn:1000-8608.2001.03.019 -
下载:
点击查看大图
图(6)
计量
- 文章访问数: 363
- HTML全文浏览量: 145
- PDF下载量: 282
- 被引次数: 0
