多年冻土区桥梁工程桩基础服役期温度场研究  

Long-term effect of a pile foundation on ground temperatures in permafrost regions

作　　者：商允虎 牛富俊 刘明浩 吴旭阳 罗京 

机构地区：[1]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《岩石力学与工程学报》2017年第9期2313-2323,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家科技支撑计划项目(2014BAG05B05);国家自然科学基金资助项目(41571065)~~

摘　　要：选取青藏高原国道214沿线低温基本稳定区查拉坪旱桥桩基和高温不稳定区花石峡试验场桩基,对其运行期内地温进行连续监测。基于现场地温实测数据,从冻土上限、冻结及融化过程3个方面,分析桩基对冻土地温的影响,显示因桩基良好的导热性能加剧了桩周冻土与大气的热交换,桩周地温年较差明显增大。结合勘察设计资料建立数学模型,应用有限元数值模拟方法就桩基对地温场的长期影响进行预测,结果表明,未来50 a气温上升2℃的情况下,桩侧冻土上限与天然上限差异有所增大,桩侧多年冻土温度升高,该现象在高温不稳定冻土区表现得更为明显。所得结论可为多年冻土区桩基设计、降温保护措施采取及运行管理措施实施提供参考。Pile foundations of Chalaping bridge in the basically stable low temperature permafrost region and Huashixia test site in the unstable warm permafrost region along the National Road G214 were selected for study. The influence of the pile foundations on the ground temperature was analyzed based on the measured data of ground temperature around the pile foundations regarding the permafrost table,the freezing and thawing processes. The results show that the relatively high thermal conductivity of the pile foundation material accelerates significantly the heat exchange between the ground and atmosphere,which results in the increase of the annual changing range of the ground temperature. The numerical models were established to investigate the long term influence of pile foundations on ground temperature. Under the assumption that the air temperature will rise 2 ℃in 50 years,the differences of the depth of permafrost table around the pile foundations and in the natural ground will increase,and the permafrost temperature near the piles will rise significantly. This phenomenon is more obvious in the unstable warm permafrost region.

关 键 词：土力学 多年冻土区 桥梁 桩基 温度场 

分 类 号：TU43[建筑科学—岩土工程]