青藏直流联网工程冻土基础传热特性分析  

ANALYSIS OF HEAT TRANSFER CHARACTERISTICS OF FROZEN SOIL FOUNDATION IN QINGHAI—TIBET DC TRANSMISSION LINE PROJECT

作　　者：俞祁浩[1] 游艳辉[1] 丁燕生[2] 王国尚 钱进[1] 胡俊[1] 郭磊[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,甘肃兰州710000 [2]国家电网公司建设部,北京100031 [3]甘肃电力公司电力经济技术研究院,甘肃兰州730050

出　　处：《岩石力学与工程学报》2013年第S2期4025-4031,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金创新研究群体科学基金项目(41121061);国家电网公司科技项目(SGJSJS(2010)935–936)

摘　　要：基于现场实测资料对冻土工程基础传热过程、温度变化结果的分析,对冻土基础稳定性变化趋势的认识至关重要。通过青藏直流线路冻土基础长期监测系统最新资料的分析研究发现,输电线路冻土基础在塔基施工完成,并经历第一次冻结期后,监测塔基周围土体总体处于冻结状态。受施工、冻土条件等因素影响,原多年冻土上限以下范围,塔基温度与天然场地存在不同程度差异;在经历融化期后,基础底部冻土依然总体处于冻结状态;在暖季升温过程中,塔基升温速率和融化深度等关键指标主要受塔基基础形式、冻土条件等因素的控制和影响;桩基础温度状况好于锥柱基础和装配式这种大开挖基础;所采用热管保护冻土的工程措施已在工程实际中发挥积极作用,但其总体效能也受到施工过程、冻土温度、塔基传热过程等因素控制和影响,地温场仍处于动态变化过程中。Based on field measurement data,the analysis,which is related to the heat transfer process of the permafrost engineering and the temperature change results,is vital to understand the stability trend of frozen soil foundation. Combined with the latest monitoring data of the frozen soil foundation long-term monitoring system in the Qinghai-Tibet direct current(DC) transmission line project,the heat transfer process of the tower foundation is analyzed preliminarily. It is found that the soil around the tower foundation is frozen overall after experiencing the first freezing period at the monitoring sites. Influenced by construction,permafrost conditions and other factors,the ground temperature around tower foundation differs from the natural filed below the permafrost table. Then,having experienced the melt period,the bottom soil of the tower foundation is frozen at the monitoring fields. During the heating process in the warm season,increasing rate of ground temperature and the thaw depth are mainly influenced by the form of tower foundations and permafrost condition. As a result,the temperature increasing at different monitoring sites varies from each other. The permafrost thermal regime near the pile foundation is better than that near the large excavation foundation such as column foundation and fabricated foundation. The heat pipes is used to protect the permafrost significantly at some sites. However,the heat pipe′s cooling effect is limited by permafrost temperature and heat transfer process at several sites when the foundation pits are excavated. Moreover,the temperature field around the foundation pit was still in dynamic changing process.

关 键 词：路基工程 青藏直流线路 冻土基础 传热特性 

分 类 号：TU445[建筑科学—岩土工程]