Analysis model of stress and deformation of permafrost subgrade with phase changing
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摘要: 基于冻土路基温度场的控制方程, 考虑水分转化为冰的相变作用对土体瞬时变形和蠕变变形的影响, 建立路基应力和变形的二维数值方程, 并通过1月份的路基冻胀力学模型, 分析冻胀带内水分相变引起的路基应力和变形的分布规律。研究发现, 在冻胀区域一定的情况下, 冻胀率的大小决定了路基表面应力和变形的极值大小; 竖向位移的最大值在坡脚处产生, 并向路基中部和左侧边界逐渐递减; 随着冻胀率的增加, 路基表面裂缝有从坡脚向路中发展的趋势; 路基表面产生最大拉应力的位置与最大竖向位移的位置基本吻合; 路中所承受的拉应力主要发生在水分集聚的相变带范围内。结果表明, 相变作用是引起路基发生冻胀病害的直接因素, 分析路基应力与变形的分布规律是研究多年冻土路基破坏机理的有效方法。Abstract: Based on the temperature field control equations of permafrost subgrade, the numerical two-dimension equations of its stress field and deformation field were put forward, the influence of water phase changing from moisture to ice on the instant deformation and creep deformation of soil was synthesized, the frost-heaving model of subgrade was experimented on january, the changing laws of the stress and deformation of permafrost subgrade surface were analyzed. It is pointed that the extreme stress and deformation of permafrost subgrade surface are determined by frost-heaving velocity within frost-heaving region; the maximum value of subgrade vertical displacement is at slope bottom, and deceases to the middle and the left boundary of subgrade little by little; with the increasing of frost-heaving velocity, the crack of subgrade surface tends to the middle of road from the slope bottom; the location of the maximum stress of subgrade surface is consistent with that of the maximum vertical displacement; road stress mainly lies in the phase changing region of moisture convergence. Analysis result shows that the phase changing of subgrade is the direct reason of subgrade frost-heaving damage, the analysis of the stress field and deformation field is an effective method to study the mechanism of permafrost subgrade damage.
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Key words:
- subgrade engineering /
- permafrost subgrade /
- phase changing /
- stress field /
- deformation field
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图 5 路中横向应力随深度的变化
Figure 5. Change of lateral stress in middle of embankment with depth
表 1 蠕变方程中的参数
Table 1. Parameters of creep equation
参数 b n ω σT/MPa T0/℃ v 拉伸试验 0.44 2.33 1 1.83 -1 10-5 
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[1] 侯曙光, 汪双杰, 黄晓明. 基于相空间重构的冻土路基变形预测[J]. 交通运输工程学报, 2005, 5(2): 35-38. doi: 10.3321/j.issn:1671-1637.2005.02.009Hou Shu-guang, Wang Shuang-jie, Huang Xiao-ming. Sub-grade deformation forecast of frozen soil based on phase space reconstruction[J]. Journal of Traffic and Transportation Engineering, 2005, 5(2): 35-38. (in Chinese) doi: 10.3321/j.issn:1671-1637.2005.02.009 [2] 王铁行, 胡长顺 . 冻土路基水分迁移数值模型[J]. 中国公路学报, 2001, 14(4): 5-8. doi: 10.3321/j.issn:1001-7372.2001.04.002Wang Tie-hang,Hu Chang-shun . A numerical model of moisture migration for frozen soil subgrade[J]. China Journal of Highway and Transport, 2001, 14(4): 5-8. (in Chinese) doi: 10.3321/j.issn:1001-7372.2001.04.002[3] 李宁, 徐彬, 陈飞熊. 冻土路基温度场、变形场和应力场的耦合分析[J]. 中国公路学报, 2006, 19(3): 1-7. doi: 10.3321/j.issn:1001-7372.2006.03.001Li Ning, Xu Bin, Chen Fei-xiong. Coupling analysis of temperature, deformation and stress field for frozen soil roadbed[J]. China Journal of Highway and Transport, 2006, 19(3): 1-7. (in Chinese) doi: 10.3321/j.issn:1001-7372.2006.03.001 [4] Newman G P, Wilson G W. Heat and mass transferin unsat-urated soils during freezing[J]. Canadian Geotechnical Journal, 1997, 34(1): 25-29. [5] Shoop S A, Bigl S R. Moisture migration during freeze andthaw of unsaturated soils: modeling and large scale experiments[J]. Cold Regions and Technology, 1997, 25(1): 33-45. doi: 10.1016/S0165-232X(96)00015-8 [6] 毛雪松, 胡长顺 , 侯仲杰. 冻土路基温度场室内足尺模型试验[J]. 长安大学学报: 自然科学版, 2004, 24(1): 30-34. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200401008.htmMao Xue-song,Hu Chang-shun , Hou Zhong-jie. Laboratory large-scale test of temperature field in permafrost sub-grade[J]. Journal of Chang an University: Natural Science Edition, 2004, 24(1): 30-34. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200401008.htm[7] Santander R E, Bubnovich V. Assessment of mass and heat transfer mechanism in unsaturated soil[J]. International Comment on Heat Transfer, 2002, 29(4): 531-545. doi: 10.1016/S0735-1933(02)00350-0 [8] 李南生, 胡巍纬, 吴青柏, 等. 冻土温度场计算中热间断面处理的理论分析[J]. 同济大学学报: 自然科学版, 2006, 34(8): 70-74. https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ200608003.htmLi Nan-sheng, Hu Wei-wei, Wu Qing-bai, et al. Disposal of discontinuous thermal interface in calculation of temperature field of permafrost[J]. Journal of Tongji University: Natural Science, 2006, 34(8): 70-74. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ200608003.htm [9] 李洪升, 刘增利, 李南生. 基于冻土水分温度和外荷载相互作用的冻胀模型[J]. 大连理工大学学报, 1998, 38(1): 29-33. https://www.cnki.com.cn/Article/CJFDTOTAL-DLLG801.006.htmLi Hong-sheng, Liu Zeng-li, Li Nan-sheng. A frost heave model based on moisture temperature and applied load inter-action infrozen soil[J]. Journal of Dalian University of Technology, 1998, 38(1): 29-33. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-DLLG801.006.htm [10] 吴紫汪, 朱林楠. 青康公路多年冻土区路堤的临界高度[J]. 冰川冻土, 1998, 20(1): 36-40. https://www.cnki.com.cn/Article/CJFDTOTAL-BCDT801.007.htmWu Zi-wang, Zhu Lin-nan. Critical height of the embankment in permafrost regions along Qinghai-Kangding highway[J]. Journal of Glaciology and Geocryology, 1998, 20(1): 36-40. (in Chi-nese). https://www.cnki.com.cn/Article/CJFDTOTAL-BCDT801.007.htm [11] 俞祁浩, 刘永智, 童长江. 青藏公路路基变形分析[J]. 冰川冻土, 2002, 24(5): 623-627. doi: 10.3969/j.issn.1000-0240.2002.05.026Yu Qi-hao, Liu Yong-zhi, Tong Chang-jiang. Analysis of the subgrade deformation of Qinghai Tibet highway[J]. Journal of Glaciology and Geocryology, 2002, 24(5): 623-627. (in Chinese) doi: 10.3969/j.issn.1000-0240.2002.05.026 [12] 姬杨蓓蓓, 马骉, 王秉纲. 冻土地区路基融沉变形对沥青路面结构的影响[J]. 中国公路学报, 2006, 19(5): 1-5. doi: 10.3321/j.issn:1001-7372.2006.05.001Ji-yang Bei-bei, Ma Biao, Wang Bing-gang. Influence of sub-grade settlement deformation in frozen soil zone on asphalt pavement structure[J]. China Journal of Highway and Transport, 2006, 19(5): 1-5. (in Chinese) doi: 10.3321/j.issn:1001-7372.2006.05.001 [13] 王铁行. 多年冻土地区路基冻胀变形分析[J]. 中国公路学报, 2005, 18(2): 1-5. doi: 10.3321/j.issn:1001-7372.2005.02.001Wang Tie-hang. Analysis of frost heave on subgrade in permafrost region[J]. China Journal of Highway and Transport, 2005, 18(2): 1-5. (in Chinese) doi: 10.3321/j.issn:1001-7372.2005.02.001 [14] 徐学祖, 王家澄, 张立新. 冻土物理学[M]. 北京: 科学出版社, 2001. [15] 中国科学院兰州冰川冻土研究所. 冻土的温度水分应力及其相互作用[M]. 兰州: 兰州大学出版社, 1989. -
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