But , even the permafrost table has highly raised the annual thermal imbalance of soil and the process of temperature rise , it is disadvantageous for the thermal stability of permafrost 对于高温多年冻土来说，尽管多年冻土上限也得到了较大幅度的抬升，但升温过程和土体年收支的不平衡都在朝著不利于多年冻土热稳定方向发展。
And , for cold permafrost , a better thermal stability situation will be developed under the condition that the temperature near the permafrost table beneath the block - stone embankment has largely dropped 然而，对于低温多年冻土来说，块石路基下部多年冻土上限附近温度有了较大的“冷量”积累，多年冻土正在朝著有利于热稳定方向发展。
During analysis of former edge slope stabilization , it is not especially that affects of freezing - melting eroding to edge slope to slide . the thesis puts forward beiyin channel was destroyed by cold freezing eroding , freezing - melting and runoff of melting snow ect 本文提出北引渠道由于地处高寒和多年冻土地区，在寒冷剥蚀、冻融剥蚀以及融雪径流等的动力作用下，渠道将发生较为严重的破坏。
Finally , this paper initially builds up a synthesis atsm design method for such areas . we sincerely hope the achievement of this research can be applied to settle the destructions and improve the performances of base course in perennially frozen soil zone 研究中，采用改进的大型马歇尔试验成型试件，试验研究结果表明，沥青稳定碎石各项路用性能优良，能够满足多年冻土地区公路沥青稳定基层的使用要求。
Permafrost has thawed , causing houses to slide off suddenly muddy cliffs ; sea ice has thinned , creating expanses of open water that rise up in ever higher storm surges ; and glaciers are melting , leading local sea levels to climb ( albeit very slightly ) 由于多年冻土融化，导致峭壁变得泥泞，房舍会突然滑落；海冰变薄导致水域扩大，造成风浪加剧；另外，冰河也正在融化，造成局部海平面上升（虽然上升幅度微小） 。
Because the road line is in mountainous region and heavy hilly area and its surface relief undulates greatly , more slope wash and dilurial layer distribution , there are more harm , for example , island shaped perennially frozen soil , drift ice and so on , which effect the stability of the road foundation 由于沿线地处山岭重丘地区，地势起伏较大，坡积物及洪积层分布较多。故岛状多年冻土、涎流冰等病害较多，影响路基的稳定。
Based on the several year data of permafrost in the region of fenghuoshan mountain , this paper not only studied the transformation of upper limit of permafrost in natural ground and roadbed but also the thawing of permafrost , and analysed quantitatively the status of heat which have entered permafrost 摘要基于对多年来风火山地区的多年冻土资料，研究了天然地区和路基下的冻土上限变化情况以及多年冻土的融化状态，并定量分析了进入多年冻土内的热状况。
Roadbed construction on permafrost will give substantial disturb for the heat and mass transfer balance between the ground surface and atmosphere , usually , roadbed construction increases the amount of absorbed heat via vegetation removal , solar radiation and increased role of water activities in the adjoining area , then cause the local degradation of the permafrost underneath , as a result may lead to damage of the roadbed 多年冻土区道路的修筑，改变了原来天然地表与外界的热交换关系，通常由于地面植被的破坏、太阳辐射和水的影响，导致进入地层中的热量增加，引起多年冻土区冻土的融化，从而导致路基面破坏。
The results demonstrate that the upper limit of permafrost in this area had declined from 1970s to the middle phase of 1990 , and permafrost has appeared degenerate tendecy , but since middle 1990s , permafrost have a stable state ; ground temperature of roadbed near the earth surface is higher than that of the natural ground , thawing time of roadbed near the earth surface is longer than that of the natural ground , the heat income within the permafrost is greater than the heat release from the permafrost during anannual period , the heat accumulation within the permafrost is temporarily appeared as temperature rising , but with the heat accumulation within permafrost growing up year by year , permafrost temperature will become higher gradually , and strong thawing of permafrost could be happened in the region 结果表明：风火山地区从20世纪70年代到90年代中期冻土上限下降，冻土出现退化现象，从90年代至今冻土趋于稳定；路基近地表地温明显高于对应天然地表下的地温，路基近地表经历的融化期长于对应天然地表，进入多年冻土区的热收支也呈现出吸热明显大于放热的周期性变化，进入多年冻土的热积累暂时以增高地温耗热为主，但随着冻土吸热量的逐年积累、冻土温度的不断升高，本区冻土可能发生强烈融化。
To check the efficiency of the insulations , by varying the thickness , the width and the position of the insulations ( expandable polystyrene insulation layer ( eps ) ; polyurethane ( pu ) ) and the material of the roadbed surface in the calculation , the maximum thawed depths during the following 50 years on permafrost under the roadbed were simulated 为了检验保温材料的效果，计算时采用改变保温材料聚苯乙烯板( eps )和聚胺脂板( pu )的厚度、宽度、埋设位置及路基表面条件，来模拟路基面下多年冻土季节最大融化深度在今后50年内随时间的变化。
