多年冻土区管道地基土开式冻胀试验

发布时间：2018-05-24 22:31

本文选题：开式冻胀试验 + 闭式冻胀试验　；参考：《天然气工业》2017年10期

【摘要】：大兴安岭地区冻土冻胀型冻害对浅埋式石油管道的安全稳定运行威胁很大。目前国内有关研究多采用闭式冻胀模拟试验,试样的含水率、干密度等因素是假设不变的,相比之下,采用各因素随试验进展而不断变化的的开式冻胀试验更能反映实际冻胀型冻害。为此,对中俄原油管道沿线5种冻土进行了开式冻胀模拟试验,测定了各种土料冻胀率与含水率,并据此分析了二者的关系,同时与闭式冻胀试验结果进行了对比分析,还应用限制位移法测定了法向冻胀力,并与静力平衡法试验结果进行了比较和差异显著性检验。试验结果表明:(1)开式冻胀试验的冻胀率大于闭式冻胀试验的冻胀率;(2)细粒土的冻胀率对土料冻胀率的影响十分显著,并且土料的毛细管作用或抽吸作用越强烈,冻胀率就越大;(3)粗粒土的冻胀率主要受含泥量的影响,其冻胀率比细粒土小;(4)法向冻胀力的大小与试验方法和试样高度的关系密切;(5)开式冻胀试验方法更适用于大兴安岭地区管道地基土的冻胀研究。结论认为:该区多年冻土区管道垫层和挖填层的土料应选用含泥量较少的砂砾或碎石,且需要采用塑性较大的黏性土做好防排水管堤。
[Abstract]:Frost-heaving frost damage of frozen soil in Daxing'anling region threatens the safety and stability of shallow buried oil pipelines. At present, close frost heaving simulation tests are mostly used in domestic researches. The moisture content and dry density of the samples are assumed to be unchanged, by contrast, The open frost heave test with various factors changing with the progress of the experiment can reflect the actual frost heave injury more effectively. For this reason, open frost heave simulation tests were carried out on five kinds of frozen soil along the route of Sino-Russian crude oil pipeline. The frost heave ratio and moisture content of various soil materials were measured, and the relationship between them was analyzed, and the results were compared with those of closed frost heave test. The normal frost heaving force was also measured by the limited displacement method, and the results were compared with the results of static equilibrium test and the difference was statistically significant. The results show that the frost heave rate of open frost heave test is greater than that of closed frost heaving test. The effect of frost heave rate of fine grained soil on soil frost heaving rate is very significant, and the capillary action or suction action of soil material is stronger than that of closed frost heaving test. The frost heaving rate of coarse grained soil is mainly affected by the content of mud. Its frost heaving rate is more suitable for the study of frost heaving of pipeline foundation soil in Daxinganling region than that of fine grained soil (4) the magnitude of normal frost heaving force is closely related to test method and specimen height. The open frost heaving test method is more suitable for the study of frost heave of pipeline foundation soil in Daxinganling area. The conclusions are as follows: in the permafrost region, sand gravel or gravel with less mud content should be used as the soil material for pipeline cushion and excavating fill in permafrost region, and the plastic clay should be used to do well the drainage pipe embankment.
【作者单位】：长春工程学院勘查与测绘工程学院;吉林大学建设工程学院;
【基金】：国家自然科学基金项目“季冻区沼泽草炭土冻胀机理研究”(编号:41502272) 长春工程学院种子基金项目“大兴安岭多年冻土区浅埋式管道冻融循环效应研究”(编号:320160017)
【分类号】：TE973

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