简介:PermafrostinChinaincludeshighlatitudepermafrostinnortheasternChina,alpinepermafrostinnorthwesternChinaandhighplateaupermafrostontheTibetanPlateau.Thehighaltitudepermafrostisabout92%ofthetotalpermafrostareainChina.Thesouthboundaryorlowerlimitoftheseasonallyfrozengroundisdefinedinaccordancewiththe0℃isothermallineofmeanairtemperatureinJanuary,whichisroughlycorrespondingtothelineextendingfromtheQinlingMountainstotheHuaiheRiverintheeastandtothesoutheastboundaryoftheTibetanPlateauinthewest.SeasonalfrozengroundoccursinlargepartsoftheterritoryinnorthernChina,includingNortheast,North,NorthwestChinaandtheTibetanPlateauexceptforpermafrostregions,andaccountingforabout55%ofthelandareaofChina.Thesouthernlimitofshort-termfrozengroundgenerallyswingssouthandnorthalongthe25°northernlatitudeline,occurringinthewetandwarmsubtropicmonsoonclimaticzone.Itsareaislessthan20%ofthelandareaofChina.
简介:摘要铁路路基是一种线形结构物,具有路线长的特点,其稳定性在很大程度上由当地自然条件所决定。路基设计时应掌握沿线的自然变化规律,采取相应的措施,以保证路基具有足够的稳定性。
简介:摘要:我国当前存在的典型的冻土区,针对这些地区特殊的自然环境,冻土区电缆的选型依旧面临诸多的挑战。本文将针对冻土区电缆的选型,及其施工进行简单的研究,并指出冻土区电缆选型过程中所面临的困难以及解决方法。希望通过本文的介绍能为冻土区电缆的选型研究工作提供一定的参考建议。