高温多年冻土区路基纵向裂缝发育的热-力耦合分析

发布时间：2018-06-20 20:44

本文选题：多年冻土路基 + 阴阳坡　；参考：《兰州理工大学学报》2014年01期

【摘要】：通过建立热-力耦合模型就阴阳坡热不对称这一因素来探讨高温不稳定冻土区纵向裂缝形成机理,得到和野外观测结果较为一致的结论:阴阳坡路肩不均匀沉降导致路基本体整体向阳坡一侧倾斜,加上阳坡土体受其下方融化盘的影响,其垂直沉降量大于阴坡一侧土体;纵向裂缝的发育是路基水平位移和竖直位移综合作用的结果,因而纵向裂缝以倾斜的形式贯穿于整个路基.纵向裂缝的发育由多年冻土这种特殊的地基土材料的强度破坏而引起;阳坡路基下方的多年冻土融化为软弱地基土,在其上土压力的作用下使路基填土中出现拉应力.提出0位移线的概念,以路基基底出现最大拉应力(或最小压应力)时路基基底是否出现0位移线作为路基是否出现纵向裂缝的判断标准,以其出现的位置作为纵向裂缝发育的位置.
[Abstract]:Based on the thermal-mechanical coupling model, the mechanism of longitudinal crack formation in high-temperature unstable frozen soil region is discussed based on the thermal asymmetry of Yinyang slope. The conclusion is consistent with the field observation results: the uneven settlement of the shoulder of the Yin-yang slope causes the subgrade body to incline to the side of the sunny slope as a whole, and the vertical settlement of the soil on the sunny slope is larger than that on the side of the overcast slope because of the influence of the melting disk under it; The development of longitudinal crack is the result of comprehensive action of horizontal displacement and vertical displacement of roadbed, so longitudinal crack runs through the whole roadbed in the form of inclination. The development of longitudinal cracks is caused by the strength failure of permafrost, which is a special foundation soil material, and the permafrost below the subgrade on the sunny slope melts into weak foundation soil, and the tensile stress appears in the subgrade fill under the action of the earth pressure on the subgrade. The concept of "0 displacement line" is put forward. Whether there is zero displacement line in the subgrade base when the maximum tensile stress (or the minimum compressive stress) appears on the subgrade base is taken as the criterion for judging whether the subgrade has longitudinal crack or not. The position of its occurrence is regarded as the position of longitudinal fracture development.
【作者单位】：兰州理工大学甘肃省土木工程防灾减灾重点实验室;兰州理工大学西部土木工程防灾减灾教育部工程研究中心;
【基金】：国家自然基金(50908111) 中科院冻土工程国家重点实验室开放基金(SKLFSE201003) 博士后科学基金(BS04200905) 甘肃省自然基金(1014RJZA026)
【分类号】：U416.16

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