Time-dependent variation distribution of fire temperature for concrete hollow thin-walled pier affected by flame fluid
-
摘要: 针对火灾场气流与焰域温度空间耦合变化时的结构响应, 通过考虑气流流速及焰围空间和结构物高度的相互作用效应, 建立了焰流场环境火灾模型。采用时间增量迭代的方法计算了焰流场温度, 研究了复合边界控制方程和对流换热与流速之间的相互关系。分析了流场中结构迎流面和侧流面温度分布状态, 研究了混凝土空心薄壁墩的环境火灾场景, 建立了焰流场结构耦合模型, 揭示了焰流效应下混凝土空心薄壁墩三维空间火温时变分布规律。研究结果表明: 火延时间为120min, 流速为3m·s-1时, 近火点温度比其他流速下温度约高100℃, 流速对火源温度呈非线性影响状态; 500℃以上的高温层在混凝土空心薄壁墩迎火面分布深度仅为7cm, 在竖向荷载作用下空心薄壁墩外层迎火面混凝土易产生层剥现象; 迎流面温度远高于侧流面温度, 背火面温度无变化; 稳态低流速场中流速的变化可改变不同温度区域的分布, 并扩大迎火面高温区面积。Abstract: For the structure response of the coupled variation of air current in fire field and flame temperature space, considering the effect of air current speed as well as the interaction effect of flame space and structure height, the surrounding fire model in flame fluid field was created. The temperature of flame fluid field was calculated by using time increment iteration method. The comprehensive boundary control equation and the relation between convection heat exchange and air current speed were studied. The temperature distribution statuses of facing-fluid side and lateral-fluid side in fluid field were analyzed, the surrounding fire scene of concrete hollow thinwalled pier was studied, the coupled model of flame fluid field was proposed, the time-dependent variation distribution law of fire temperature for concrete hollow thin-walled pier affected by flame fluid was revealed. Analysis result indicates that when fire time is 120 min and air current speed is 3 m·s-1, the temperature near fire source is about 100℃ higher than that at other air current speeds, the influence of air current speed on fire source temperature is nonlinear. Thedistribution depth of high temperature layer (higher than 500℃) on facing-fire side is only 7 cm, the outer facing-fire side concrete of hollow thin-walled pier strips easily under vertical load. Temperature on facing-fluid side is much higher than temperature on lateral-fluid side, temperature on far side of fire does not change. The distribution domains of different temperatures can be changed with the variation of air current speed in steady low fluid field, and the high temperature area on facing-fire side can be enlarged.
-
图 2 混凝土空心薄壁墩环境火灾场景
Figure 2. Surrounding fire scene of concrete hollow thin-walled pier
图 3 混凝土空心薄壁墩截面尺寸及钢筋构造
Figure 3. Section dimension and steel constitution of concrete hollow thin-walled pier
图 6 各测点温度时变分布
Figure 6. Temperature time-dependent variation distributions at measuring points
图 7 不同流速下温度时变分布
Figure 7. Temperature time-dependent variation distributions at different fluid speeds
-
[1] GARLOCK M, PAYA-ZAFORTEZA I, KODUR V, et al. Fire hazard in bridges: review, assessment and repair strategies[J]. Engineering Structures, 2012, 35 (1): 89-98. [2] KODUR V, DWAIKAT M. A numerical model for predicting the fire resistance of reinforced concrete beams[J]. Cement and Concrete Composites, 2008, 30 (5): 431-443. doi: 10.1016/j.cemconcomp.2007.08.012 [3] NUBISSIE A, NGAMIE N A, WOAFO P. Dynamical behavior of a wooden beam under mechanical loading and fire[J]. Materials and Design, 2011, 32 (3): 1331-1336. doi: 10.1016/j.matdes.2010.09.020 [4] SHAHID I, HARICHANDRAN R S. Capacity reduction and fire load factors for LRFD of steel columns exposed to fire[J]. Fire Safety Journal, 2011, 46 (5): 234-242. doi: 10.1016/j.firesaf.2011.02.005 [5] CAPUA D D, MARI A R. Nonlinear analysis of reinforced concrete cross-sections exposed to fire[J]. Fire Safety Journal, 2007, 42 (2): 139-149. doi: 10.1016/j.firesaf.2006.08.009 [6] 吴珂, 黄志义, 徐兴. 长隧道火灾中沥青路面燃烧的热效应研究[J]. 中国公路学报, 2009, 22 (2): 77-81. doi: 10.3321/j.issn:1001-7372.2009.02.014WU Ke, HUANG Zhi-yi, XU Xing. Research on thermal effect of asphalt pavement combustion in long tunnel fires[J]. China Journal of Highway and Transport, 2009, 22 (2): 77-81. (in Chinese). doi: 10.3321/j.issn:1001-7372.2009.02.014 [7] 欧阳志为. 足尺预应力混凝土梁板抗火性能研究[D]. 哈尔滨: 哈尔滨工业大学, 2009.OUYANG Zhi-wei. Research on fire resistance performance of full-scale prestressed concrete beams and slabs[D]. Harbin: Harbin Institute of Technology, 2009. (in Chinese). [8] 蒋首超, 李国强, 周宏宇, 等. 钢-混凝土组合楼盖抗火性能的试验研究[J]. 建筑结构学报, 2004, 25 (3): 45-51. doi: 10.3321/j.issn:1000-6869.2004.03.007JIANG Shou-chao, LI Guo-qiang, ZHOU Hong-yu, et al. Experimental study of behavior of steel-concrete composite slabs subjected to fire[J]. Journal of Building Structures, 2004, 25 (3): 45-51. (in Chinese). doi: 10.3321/j.issn:1000-6869.2004.03.007 [9] 陆洲导, 俞可权. 高温后混凝土断裂韧度及软化本构曲线确定[J]. 同济大学学报: 自然科学版, 2012, 40 (9): 1306-1311. doi: 10.3969/j.issn.0253-374x.2012.09.005LU Zhou-dao, YU Ke-quan. Determination of residual fracture toughness and softening traction-separation law of post-fire concrete[J]. Journal of Tongji University: Natural Science, 2012, 40 (9): 1306-1311. (in Chinese). doi: 10.3969/j.issn.0253-374x.2012.09.005 [10] 周勇超, 胡圣能, 宋磊, 等. 钢-混凝土组合梁的温度骤变效应分析[J]. 交通运输工程学报, 2013, 13 (1): 20-26. doi: 10.3969/j.issn.1671-1637.2013.01.004ZHOU Yong-chao, HU Sheng-neng, SONG Lei, et al. Effect analysis of steel-concrete composite beam caused by sudden change of temperature[J]. Journal of Traffic and Transportation Engineering, 2013, 13 (1): 20-26. (in Chinese). doi: 10.3969/j.issn.1671-1637.2013.01.004 [11] 钟占荣, 周建军, 邹样辉, 等. 山地林火蔓延模型的研究[J]. 火灾科学, 2001, 10 (2): 83-87. doi: 10.3969/j.issn.1004-5309.2001.02.006ZHONG Zhan-rong, ZHOU Jian-jun, ZOU Yang-hui, et al. Study on the model of wildland fire spread[J]. Fire Safety Science, 2001, 10 (2): 83-87. (in Chinese). doi: 10.3969/j.issn.1004-5309.2001.02.006 [12] 王志春, 宋丽莉, 何秋生, 等. 风速随高度变化的曲线模型分析[J]. 热带气象学报, 2007, 23 (6): 90-92. https://www.cnki.com.cn/Article/CJFDTOTAL-RDQX200706025.htmWANG Zhi-chun, SONG Li-li, HE Qiu-sheng, et al. Model analysis of curve fitting of wind speed and its height[J]. Journal of Tropical Meteorology, 2007, 23 (6): 90-92. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-RDQX200706025.htm [13] 魏东, 梁强. 消防水幕衰减火灾辐射热的理论研究[J]. 中国安全科学学报, 2008, 18 (10): 75-81. doi: 10.3969/j.issn.1003-3033.2008.10.013WEI Dong, LIANG Qiang. Theoretical study on fire radiation attenuation with water curtains[J]. China Safety Science Journal, 2008, 18 (10): 75-81. (in Chinese). doi: 10.3969/j.issn.1003-3033.2008.10.013 [14] 石龙, 张瑞芳, 谢启源, 等. 大空间内着火位置对火灾增长的影响[J]. 中国工程科学, 2008, 10 (11): 37-42. doi: 10.3969/j.issn.1009-1742.2008.11.007SHI Long, ZHANG Rui-fang, XIE Qi-yuan, et al. Effect analysis of fire location on fire growth in large space[J]. China Engineering Science, 2008, 10 (11): 37-42. (in Chinese). doi: 10.3969/j.issn.1009-1742.2008.11.007 [15] 刘文燕, 黄鼎业, 华毅杰. 混凝土表面对流换热系数测试方法探讨[J]. 四川建筑科学研究, 2004, 30 (4): 87-89. doi: 10.3969/j.issn.1008-1933.2004.04.033LIU Wen-yan, HUANG Ding-ye, HUA Yi-jie. Probe into test method of heat convection coefficient of concrete[J]. Sichuan Building Science, 2004, 30 (4): 87-89. (in Chinese). doi: 10.3969/j.issn.1008-1933.2004.04.033 [16] 徐志胜, 吴振营, 何佳. 池火灾模型在安全评价中应用的研究[J]. 灾害学, 2007, 22 (4): 25-28. doi: 10.3969/j.issn.1000-811X.2007.04.006XU Zhi-sheng, WU Zhen-ying, HE Jia. Study on pool fire model applying to the safety assessment[J]. Journal of Catastrophology, 2007, 22 (4): 25-28. (in Chinese). doi: 10.3969/j.issn.1000-811X.2007.04.006 [17] 张岗, 贺拴海, 宋一凡, 等. 钢筋混凝土梁桥火灾高温安全评价[J]. 安全与环境学报, 2008, 7 (3): 153-157. doi: 10.3969/j.issn.1009-6094.2008.03.037ZHANG Gang, HE Shuan-hai, SONG Yi-fan, et al. Safety evaluation for reinforcement concrete girders exposed to fire[J]. Journal of Safety and Environment, 2008, 7 (3): 153-157. (in Chinese). doi: 10.3969/j.issn.1009-6094.2008.03.037 [18] 张岗, 贺拴海, 宋一凡, 等. 火灾高温下钢筋混凝土梁桥非线性计算方法[J]. 西安建筑科技大学学报: 自然科学版, 2008, 40 (3): 317-322. doi: 10.3969/j.issn.1006-7930.2008.03.005ZHANG Gang, HE Shuan-hai, SONG Yi-fan, et al. Nonlinear computation method for simply supported beam of reinforcement concrete exposed to fire[J]. Journal of Xi'an University of Architecture and Technology: Natural Science Edition, 2008, 40 (3): 317-322. (in Chinese). doi: 10.3969/j.issn.1006-7930.2008.03.005 [19] 张岗, 贺拴海, 郭琦, 等. 火灾下钢筋混凝土梁桥高温场形变分析[J]. 长安大学学报: 自然科学版, 2009, 29 (1): 54-58. doi: 10.3321/j.issn:1671-8879.2009.01.012ZHANG Gang, HE Shuan-hai, GUO Qi, et al. High temperature deformation of reinforcement concrete beam bridges exposed to fire[J]. Journal of Chang'an University: Natural Science Edition, 2009, 29 (1): 54-58. (in Chinese). doi: 10.3321/j.issn:1671-8879.2009.01.012 [20] 张岗, 贺拴海, 王翠娟. 整跨火荷载下PC薄壁多室变宽箱梁桥的变形[J]. 长安大学学报: 自然科学版, 2011, 31 (2): 42-46. doi: 10.3969/j.issn.1671-8879.2011.02.010ZHANG Gang, HE Shuan-hai, WANG Cui-juan. Deformation analysis of pre-stressed concrete multi-cell thin-wall variable width box girders bridge exposed to co-action fire and load[J]. Journal of Chang'an University: Natural Science Edition, 2011, 31 (2): 42-46. (in Chinese). doi: 10.3969/j.issn.1671-8879.2011.02.010 [21] 张岗. PC宽异薄壁箱梁火灾高温场形变分析[J]. 解放军理工大学学报: 自然科学版, 2011, 12 (2): 165-171. https://www.cnki.com.cn/Article/CJFDTOTAL-JFJL201102012.htmZHANG Gang. Deformation analysis of concrete thin-wall box girders for width and difference exposed to fire[J]. Journal of PLA University of Science and Technology: Natural Science Edition, 2011, 12 (2): 165-171. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JFJL201102012.htm [22] 张岗, 王翠娟, 贺拴海, 等. 桥面火灾下多梁式混凝土T型梁桥抗火性能[J]. 长安大学学报: 自然科学版, 2013, 33 (5): 52-56. doi: 10.3969/j.issn.1671-8879.2013.05.010ZHANG Gang, WANG Cui-juan, HE Shuan-hai, et al. Fireresistant performance of multi-beam concrete T-shape girder bridge exposed to deck fire[J]. Journal of Chang'an University: Natural Science Edition, 2013, 33 (5): 52-56. (in Chinese). doi: 10.3969/j.issn.1671-8879.2013.05.010 [23] 罗桑, 苏凯, 钱振东, 等. 闵浦大桥环氧沥青混凝土铺装施工时温节点研究[J]. 筑路机械与施工机械化, 2010, 27 (8): 66-68. https://www.cnki.com.cn/Article/CJFDTOTAL-ZLJX201008033.htmLUO Sang, SU Kai, QIAN Zhen-dong, et al. Research on key time and temperature nodes of epoxy asphalt concrete pavement on minpu bridge[J]. Road Machinery and Construction Mechanization, 2010, 27 (8): 66-68. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-ZLJX201008033.htm [24] 郑文忠, 闫凯, 王英. 预应力混凝土结构抗火研究进展[J]. 建筑结构学报, 2011, 32 (12): 52-61. https://www.cnki.com.cn/Article/CJFDTOTAL-JZJB201112007.htmZHENG Wen-zhong, YAN Kai, WANG Ying. Progress of research on fire resistance of prestressed concrete structures[J]. Journal of Building Structures, 2011, 32 (12): 52-61. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JZJB201112007.htm [25] 张岗, 贺拴海, 宋一凡. 混凝土箱梁水化热温度损伤修正耦合方法[J]. 交通运输工程学报, 2008, 8 (1): 54-60. http://transport.chd.edu.cn/article/id/200801012ZHANG Gang, HE Shuan-hai, SONG Yi-fan. Updating coupling method of hydration heat temperature damage for concrete box girder[J]. Journal of Traffic and Transportation Engineering, 2008, 8 (1): 54-60. (in Chinese). http://transport.chd.edu.cn/article/id/200801012 [26] 李国强, 吴波, 蒋首超. 工程结构抗火研究进展与建议[J]. 建筑钢结构进展, 2010, 12 (5): 13-18. https://www.cnki.com.cn/Article/CJFDTOTAL-JZJZ201005004.htmLI Guo-qiang, WU Bo, JIANG Shou-chao. State-of-the-art and suggestions of research on fire-resistance of structures[J]. Progress in Steel Building Structures, 2010, 12 (5): 13-18. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JZJZ201005004.htm [27] 熊焱, 屈文俊, 张翔. 灾受损混凝土再碱化修复过程中的导电原理分析[J]. 建筑科学与工程学报, 2013, 30 (1): 55-59. https://www.cnki.com.cn/Article/CJFDTOTAL-XBJG201301010.htmXIONG Yan, QU Wen-jun, ZHANG Xiang. Analysis of conductivity mechanism of realkalization repair on fire damaged concrete[J]. Journal of Architecture and Civil Engineering, 2013, 30 (1): 55-59. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-XBJG201301010.htm [28] 张建荣, 刘照球. 混凝土对流换热系数的风洞实验研究[J]. 土木工程学报, 2006, 39 (9): 39-43. https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200609005.htmZHANG Jian-rong, LIU Zhao-qiu. A study on the convective heat transfer coefficient of concrete in wind tunnel experiment[J]. China Engineering Journal, 2006, 39 (9): 39-43. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-TMGC200609005.htm -
下载:
点击查看大图
图(7) / 表(3)
计量
- 文章访问数: 522
- HTML全文浏览量: 79
- PDF下载量: 670
- 被引次数: 0
