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青藏交直流联网工程是继青藏公路、青藏铁路等之后,在青藏高原多年冻土区建设的另一种新结构的冻土工程.系统地分析了青藏直流线冻土工程与其它工程的差异,并就该工程冻土基础温度、水分、应力和应变监测系统的建立和观测要素,以及初步观测结果等问题进行了讨论.通过对2011年全年观测数据分析发现,整个监测系统可以准确、及时反映输电线路冻土基础的不同性状和特征,可以反映影响塔基稳定性的主要因素及其变化趋势.初步观测结果表明,在不同时段,监测塔式基础底部总体处于冻结状态、塔基基本稳定,但个别监测塔基地温增温幅度、上限融化深度较大,沉降变形呈现增加趋势.鉴于工程完工和荷载作用的时效性,塔基稳定性应处于动态变化过程之中.为正确评价塔基稳定性,需要对塔基回填土的冻融、水热变化和塔基变形等重要过程进行长期监测研究.
Qinghai-Tibet AC-DC networking project is another new structure of frozen soil construction in the permafrost region of Qinghai-Tibet Platea, following Qinghai-Tibet Highway, Qinghai-Tibet Railway, etc. The difference between Qinghai-Tibet DC line frozen soil engineering and other projects is systematically analyzed, And discussed the establishment and observation elements of the temperature, moisture, stress and strain monitoring system of the project permafrost foundation, as well as the preliminary observation results and other issues.Analysis of the full year observation data in 2011 found that the whole monitoring system can be accurate and timely The reflection of the different characters and characteristics of the foundation of the permafrost on the transmission line can reflect the main factors affecting the stability of the tower and its changing trend.The preliminary observation results show that the base of the monitoring tower is in a freezing state at all time and the base of the tower is basically stable , But individual monitoring of temperature increase of tower base, the upper limit of the melting depth is larger, the settlement deformation shows an increasing trend in view of the timeliness of the completion of the project and the load, the stability of the tower should be in the dynamic process of change.To evaluate the right tower Stability, the need for long-term monitoring of the important processes such as freeze-thaw, hydrothermal changes and deformation of the tower base backfill Study.