【作者】 张艳芳；

【导师】 刘建坤；

【作者基本信息】 北京交通大学 ， 岩土工程， 2014， 硕士

【摘要】 本文在中俄原油管道这一国家重大工程项目背景下,以东北多年冻土区的气候环境、地质条件为基础,以穿越该地区的原油管道为研究对象,运用ANSYS有限元分析软件,对管道修建后50年内土体中的温度场进行了数值计算,根据计算结果研究了埋地输油管道的铺设对多年冻土温度的影响,得出的主要结论如下：1.中俄原油管道漠河至大庆段沿线多年冻土分布复杂,工程地质特征差异较大,热稳定性较差,埋设输油管道对多年冻土的影响极大。2.同一条管道,在不同季节温度条件下,管道周围土壤温度场的分布差异很大；同一季节,管道附近与距离管道较远处的地温(沿深度方向的温度)分布亦不相同。3.输油管道对低温冻土区冻土的扰动较小,运营第10年开始冻土基本达到平衡状态；而高温冻土区受到管道的扰动较强烈,此时可以通过减小管道顶部埋深或铺设保温材料来保持多年冻土的稳定性。4.铺设保温材料能有效减小多年冻土的最大融化深度,保温层越厚,管道对多年冻土的扰动越小；低温冻土区需铺设5～8cm的保温层,高温冻土区则应铺设大于8cm的保温层或者采用其它降温措施来保护冻土。5.管道顶部埋深对多年冻土温度场影响极大,埋深越大,管底下最大融化深度越大,多年冻土稳定性越差,仅从温度场的角度来说低温冻土区的埋深可选择在0.8～1.5m范围内。6.平均输油温度对多年冻土温度场的分布规律有很大的影响,随着平均油温的增加,冻土的最大融化深度逐渐加大,工程中应控制油温过高。更多还原

【Abstract】 ABSTRACT:Based on the national important project of China-Russia oil pipeline engineering, ANSYS finite element analysis software was used to calculate the temperature field within50years after construction of the pipeline that is related to climatic environment and geological conditions in northeast permafrost areas. The following conclusions can be shown as below:(1) The permafrost along the Mohe-Daqing section of the China-Russia crude oil pipeline, with complex distribution, quite different engineering geological behavior, and poor thermal stability, will be greatly influenced by the oil pipeline.(2) For a certain pipeline, the temperature field distribution of soils around the pipeline varies considerably under different seasonal temperatures; The ground temperature distribution nearby the pipeline is also different from far away.(3) Soils around the pipeline in low temperature permafrost regions are relatively stable, which reach balanced state from the tenth year. Soils in warm permafrost regions are affected significantly, solved by reducing the buried depth of the pipe top part or laying insulation materials.(4) By laying insulation materials can reduce the maximum thawing depth. With a larger thickness of the insulation layer, the disturbances on permafrost will be smaller. The insulation layer thickness of5-8cm is needed in low temperature permafrost regions while in warm permafrost regions the thickness should be larger than8cm or other cooling measures should be taken to protect the permafrost.(5) The maximum thawing depth below the pipe increases with the increase of the buried depth of the pipe top part which affects the temperature field distribution significantly. The overlaying soil thickness of pipe top part can be selected with the range of0.8to1.5m in low temperature permafrost regions, only from the perspective of the temperature field.(6) The average oil temperature has considerable influence on the temperature field distribution. The thawing depth increases with the increase of average oil temperature and the oil temperature should not be too high.更多还原