中俄原油管道(漠河—大庆段)地基土融沉稳定性评价研究

THAW-STABILITY ASSESSMENT OF THE PERMAFROST FOUNDATION SOIL ALONG THE PROPOSED CHINA-RUSSIA CRUDE OIL PIPELINE FROM MO′HE TO DAQING

中国-俄罗斯原油管道工程(简称中俄原油管道)规划全长1,035 km,中国境内段965 km,俄罗斯境内段70 km。中俄原油管道(漠河—大庆段)穿越约500 km多年冻土区,沿途地形起伏,水系和沼泽发育,冻土工程地质条件复杂,影响因素多样。提出以管道地基土的最大融沉变形量为评价准则,以多年冻土的年平均地温和含冰量为评价指标,对多年冻土进行工程分类,并依据分类结果进行评价。依据计算结果以-1.0℃和-2.0℃对中俄原油管道沿线多年冻土进行冻土工程分类。具体分为:稳定型、过渡型、高温不稳定型(-1.0^-2.0℃)以及极高温极不稳定型(≥-1.0℃)。分别对应良好、较好、不良以及极差评价结果,并以此为基准选择传统埋设、埋设、埋设+换填、埋设+换填+隔热或架设等管基设计原则。对管道沿线约430 km多年冻土区进行了详细和逐段的评价。评价结果表明评价指标简单、实用,评价结果合理、恰当,可推荐在其它多年冻土区类似管道工程中使用。

The proposed China-Russia Crude Oil Pipeline runs through the permafrost area for about 500 km,across mountains,forests and wetlands with complicated frozen-ground engineering geological conditions.The maximum allowable thaw settlement of pipeline foundation soils is chosen as the assessment criterion.Using the meaning annual ground temperature and ice content of permafrost as the assessment indices,the permafrost along the pipeline route was classified into four types（according to-1.0 and-2.0℃）： thermally-stable permafrost and-transitory cold permafrost,thaw-unstable warm permafrost（-1.0～-2.0℃）and extremely unstable warm permafrost（≥-1.0℃）.The recommended construction modes include conventional burial,insulated burial,drainage control,refill with non-frost-susceptilble and/or thaw-stable soils,elevation,and even above ground bent/dike with or without drainage control.Using this assessment system,about 430km of permafrost of the pipeline route has been evaluated in detail.The assessment system is simple in criteria,and has resulted in appropriate and practical products.