研究目的:由于温度和水分的介入以及运营条件的诱发,使运营期间冻土路基工程状态的研究变得更为复杂.通过对运营初期多年冻土路基工程状态的现场调查和监测,从路基变形、地温变化、水热环境三个方面研究运营初期多年冻土区路基的工程状态,提出路基裂缝病害的解决措施,为铁路安全运营和养护工作服务.研究结论:(I)多年冻土区路基工程在运营初期,路基变形总体呈衰减趋势,已经趋于稳定.(2)路基大多数断面多年冻土上限上升和上限形态趋于稳定,地基冷储量增加,多年冻土上限上升是在降低土体温度的基础上实现的.(3)路基工程状态变化首先是地温场的变化改变了发生变形的土层位置和厚度,同时地温场的不对称造成变形差异,诱发裂缝发生,水热环境的变化导致裂缝发展.(4)采用热学不对称的路基结构,能减缓上限形态的不对称性,从而减小路基横向差异变形,抑制路基工程裂缝的发生和发展.%Research purposes:Studies on the status of subgrade engineering in permafrost region is complicated by the intervention of temperature and water and railway operating conditions. Based on in - site investigation and monitoring during the early operation of the QTR, this paper studied the status of subgrade engineering from three aspects, subgrade deformation, geothermal changes and hydrothermal conditions, and proposed solutions to subgrade cracks to ensure railway safely and conservation.rnResearch conclusions; (1) During the Early Operation, the subgrade engineering in Permafrost Region Railway, we found that the overall deformation has been on the decline and subgrade deformation has stabilized. (2)The upper limits of permafrost in most subgrade sections have increased, their statuses have stabilized and the cold reserves of bases have increased. The increase in upper limits is a result of the decrease in soil temperature. (3) The status of subgrade engineering has changed because the changes in geothermal field have altered the places and soil depths of deformations. At the same time, the asymmetry field causes deformation differences and deduces cracks. Hydrothermal changes will result in cracks. (4) Asymmetry thermotics in subgrade structure will soften the asymmetry of upper limits, thus reduce the difference of horizontal deformations and prevent cracks.
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