基于过渡段相变三维传热分析模型，对未来30 年路桥过渡段温度场进行分析与预测，研究了过渡段阴阳坡时空效应对路桥过渡段长期热稳定性的影响。计算结果表明：随着路桥过渡段运营时间的增长，各纵断面最大融化深度部位逐渐由过渡段转移到台背后路基，各横断面最大融深及最大融化速率位置均由阳坡坡脚转移到路基中心与阳坡路肩之间，相同运营时间，沿台背方向阴坡坡脚冻土上限变化并不明显；随着运营时间的增长，各横断面阳坡坡脚融化速率均大于天然冻土地基融化速率；各横断面除阳坡坡脚的其余部位在运营25 年以前，人为上限退化率基本小于天然冻土上限，运营25 年后，人为上限退化率逐渐大于天然冻土上限。
A 3-D numerical simulation model of the permafrost roadbed-bridge transition section thermal field is built and the finite element method is adopted to predict and compare the thermal field for different transition section heights and different types of permafrost by raising temperature by 2.6℃ in the coming 50 years. The calculated results show that with the time, the maximum thawing depth profile parts move gradually from the transition section to the place behind the embankment,and the positions of the largest cross-sectional thawing depth and the maximum thawing rate move from the northern slope foot between the slope shoulders to the subgrade center. The cross sectional northern slope foot thawing rate becomes greater than the natural thawing permafrost foundation rate. For the rest parts of the transect before the operational 25 years, the artificial permafrost table degradation rate is lower than the natural permafrost table, and 25 years later, the artificial permafrost table degradation rate is higher than that of the natural permafrost table gradually.
[1] Yershov E D. General geocryology[M]. Cambridge: Cambridge University Press, 1998.
[2] 周幼吾, 郭东信, 邱国庆, 等. 中国冻土[M]. 北京: 科学出版社, 2000: 37-41. Zhuo Youwu, Guo Dongxin, Qiu Guoqing, et al. Geocryology in China[M]. Beijing: Science Press, 2000: 37-41.
[3] 张军, 郑俊杰, 马强, 等. 路桥过渡段路堤加筋现场试验和数值模拟分析[J]. 华中科技大学学报: 自然科学版, 2011, 39(9): 87-90. Zhang Jun, Zheng Junjie, Ma Qiang, et al. Experimental and numerical simulation analysis on geosynthetic reinforced embankment at bridge approaches[J]. Journal of Huazhong University of Science and Technology: Nature Science, 2011, 39(9): 87-90.
[4] Graeme D, Skinnera R, Kerry R. Design and behaviour of a geosynthetic reinforced retaining wall and bridge abutment on a yielding foundation[J]. Geotextiles and Geomembranes, 2005, 23: 234-260.
[5] 聂如松, 冷伍明, 律文田. 软基台后路基填土对桥台桩基侧向影响的试验研究[J]. 岩土工程学报, 2005, 27(12): 1487-1490. Nie Rusong, Leng Wuming, Lü Wentian. Experimental study on lateral influence of embankment construction on piles in soft clay[J]. Chinese Journal of Geotechnical Engineering, 2005, 27(12): 1487-1490.
[6] 陈雪华, 律文田, 王永和. 台后填土对桥台桩基的影响分析[J]. 岩土工程学报, 2006, 28(7): 910-913. Chen Xuehua, Lü Wentian, Wang Yonghe. In-situ test of negative friction of abutment piles in soft soil[J]. Chinese Journal of Geotechnical Engineering, 2006, 28(7): 910-913.
[7] 刘建坤, 鲍维猛, 韩小刚, 等. 多年冻土区路桥过渡段一种新结构的试验观测与分析[J]. 冰川冻土, 2004, 26(6): 800-805. Liu Jiankun, Bao Weimeng, Han Xiaogang, et al. Observation and analysis of a new type embankment-bridge transition section in permafrost regions[J]. Journal of Glaciology and Geocryology, 2004, 26 (6): 800-805.
[8] 田亚护, 刘建坤, 彭丽云. 多年冻土区路桥过渡段变形及地温场试验[J]. 中国公路学报, 2007, 20(4): 19-24. Tian Yahu, Liu Jiankun, Peng Liyun. Experiment on ground temperature field and deformation of bridge-subgrade transition section in permafrost regions[J]. China Journal of Highway and Transport, 2007, 20(4): 19-24.
[9] 牛富俊, 林战举, 鲁嘉濠, 等. 青藏铁路路桥过渡段沉降变形影响因素分析[J]. 岩土力学, 2011, 32(S1): 372-377. Niu Fujun, Lin Zhanju, Lu Jiahao, et al. Study of the influencing factors of roadbed settlement in embankment-bridge transition section along Qinghai-Tibet Railway[J]. Rock and Soil Mechanics, 2011, 32 (S1): 372-377.
[10] 马巍, 穆彦虎, 李国玉, 等. 多年冻土区铁路路基热状况对工程扰动及气候变化的响应[J]. 中国科学: 地球科学, 2013, 43(3): 478-489. Ma Wei, Mu Yanhu, Li Guoyu, et al. Responses of embankment thermal regime to engineering activities and climate change along the Qinghai-Tibet Railway[J]. Scientia Sinica Terrae, 2013, 43(3): 478-489.
[11] 马辉, 刘建坤, 张弥, 等. 青藏铁路建设中的冻土工程问题及其应对措施[J]. 土木工程学报, 2006, 39(2): 85-106. Ma Hui, Liu Jiankun, Zhang Mi, et al. Frozen soil problem s in Qinghai-Tibet railway construction and engineering measures[J]. China Civil Engineering Joural, 2006, 39(2): 85-106.
[12] 吴紫汪, 程国栋, 朱林楠, 等. 冻土路基工程[M]. 兰州: 兰州大学出版社, 1988. Wu Ziwang, Cheng Guodong, Zhu Linnan, et al. Roadbed engineering in permafrost regions[M]. Lanzhou: Lanzhou University Press, 1988.
[13] 徐敩祖, 王家澄, 张立新. 冻土物理学[M]. 北京: 科学出版社, 2010. Xu Xiaozu, Wang Jiacheng, Zhang Lixin. Physics of frozen soil[M]. Beijing: Science Press, 2010.
[14] 史聪慧. 青藏铁路清水河高温高含冰量冻土区“以桥代路”工程稳定性研究[D]. 北京: 中国科学院研究生院, 2007. Shi Conghui. Research of engineering stability for the bridge-insteadof-embankment structure[D]. Beijing: Graduate School of the Chinese Academy, 2007
[15] 赖远明, 张明义, 李双洋, 等. 寒区工程理论与应用[M]. 北京: 科学出版社, 2009: 52-53. Lai Yuanming, Zhang Mingyi, Li Shuangyang, et al. Theory and application of cold regions engineering[J]. Beijing: Science Press, 2009: 52-53.
[16] Qin D H. The comprehensive evaluating report on the environment evolvement in west China[M]. Beijing: Science Press, 2002, 57-58.
