【作者】 陈情来；

【导师】 谭成轩； 张永双；

【作者基本信息】 中国地质科学院 ， 地质工程， 2007， 博士

【摘要】 多年冻土的工程地质特性及其相关的工程地质问题是当前油气管道工程建设中所面临的全球性工程难题。本文以正在规划的中俄原油管道工程为例，从我国高纬度多年冻土区管道工程建设可能遇到的工程地质问题出发，在总结中国高纬度地区多年冻土的主要特征和分布规律的基础上，结合研究区铁道、公路等线状工程建设实践，阐述了与多年冻土有关的工程地质问题及其形成机理；对多年冻土的工程地质特性进行了系统测试和统计分析；结合中俄原油管道规划，对管道沿线多年冻土的工程地质条件进行了综合评价，具有重要的理论和实际意义。分析研究表明，研究区内多年冻土的空间分布与纬度、海拔、微地貌和地热交换条件等因素有密切的关系。总体上，多年冻土呈不连续分布，自北向南由大片岛状多年冻土区逐渐过渡为零星岛状多年冻土区。由于全球气候变暖，多年冻土的退化趋势比较明显，从研究区多年冻土的退化表现来看，北部多年冻土退化主要表现为量变过程，而南部质变过程表现突出。野外地质调查表明，中俄原油管道工程沿线途经的河漫滩、阶地附近，多年冻土类型以多冰—富冰—饱冰冻土为主，在沼泽地段分布有含土冰层。本文根据大量实验数据，系统阐述了研究区多年冻土的工程地质特性，包括基本物理指标、热物理指标、力学性质和融化压缩性质，在此基础上统计分析了冻土的强度与负温度、岩性、含水量和外力作用时间等因素之间的相关性。冻土与管道间相互作用的模拟结果表明，冬季埋地管道会造成土壤温度降低，容易形成对管道的上抬力；夏季埋地管道易导致冻土融化；冻土的冻胀和融沉均能使管道产生弯曲变形。通过对冻土与基础间的相互作用过程分析认为，建(构)筑物的恒载不能克服冻胀力是产生基础冻胀变形破坏的主导因素，冻土融化时压缩系数增大是正融土产生融沉的根本原因。在工程实践中，注重多年冻土区工程经验和测试数据的积累是十分必要的。本文获得的中俄原油管道工程沿线多年冻土工程特性的基础数据及统计分析成果，对于今后高纬度多年冻土区冻土工程地质条件的综合评价以及冻土工程地质问题的解决具有较高的实用性和推广价值。更多还原

【Abstract】 The engineering geological character of permafrost and its coherent problems are the global difficult engineering problems which are suffered during the oil and gas pipeline construction. Therefore, this study takes the Russia-China oil pipeline project being planed now for example, starting from the engineering geological problems which might be met in the pipeline construction in the permafrost region of nigh latitude in China, on the basis of the generalization of the main character and distribution regulation of the permafrost region of high latitudes in China, and associated with the linear engineering project construction of railway and road, the essay explains some engineering geological problems of perma frost and its forming mechanics. The study makes testing systematically and makes statistic analysis or the engineering geological character of permafrost, and the essay also makes synthesis appraisal of the engineering geology condition of permafrost along the Russian-China Oil Pipelin Project, which is beneficial with high theoretical and practical significance.The analysis and research indicate that the permafrost distribution has close relation with the factors of latitude, elevation, tiny physiognomy, terrestrial heat and so on. On the whole, the distribution of permafrost is not continuous, which transfers from the north of large island area permafrost distributing to the south of sporadic area permafrost distributing. Owing to the globe getting warmer, the degradation trend of permafrost is apparent. According to the permafrost degradation of the research, the degradation in the north mainly represents a quantitative change, while in the south it represents a qualitative change.The field geological research indicates that the permafrost type is mainly of much ice- more ice - most ice, and there are ice layers containing soil distributing in the swampland area. This essay systemically expatiates the engineering geological character of permafrost in study area based on large quantity of experiment data, which include basic physical index, thermo-physical index, dynamics character, as well as the character of melt and compression. The study also statistically analyses the correlation relation among the factors of intensity and negative temperature of permafrost, lithology, water content, and the external force time.The simulating result of the interactivity between the frost and the pipeline indicates that the buried pipes can lower the soil temperature and form upward forces to the pipeline in winter, while in summer the buried pipes will cause the frozen soil melt, both the frost heave and the thaw collapse can make the pipeline distorted and bent. By analyzing the interactivity between the frost and basic foundation, the permanent load of the building which can not overcome the frost-heave force is the main cause of leading to foundation frost heave and damage, and the magnification of the compression coefficient during the frozen soil melting is the ultimate cause which leads the frozen soil thaw collapse.It’s necessary to accumulate the engineering experience and experimental data of the perma frost region during the engineering practice. The basic testing data and the statistic analysis of the perma frost character obtained in this study along the Russia-China crude oil pipeline have high practicability and popularizing value for the frozen soil engineering geological synthesis appraisal of high latitude permafrost region and the solution of the frozen soil engineering geological problems.更多还原