多年冻土地区隔热板路基工作机理研究

利用非线性有限元方法,对多年冻土地区隔热板路基温度场的变化特征进行数值模拟,进而对隔热板路基的工作机理进行研究。研究表明:路基内部铺设隔热板后,路基温度场的分布特征受到很大影响;板下土体与外界的热交换强度大大减小,对外部温度变化的响应速度显著降低;隔热板在不同季节起到不同的作用,在夏季阻止外部热量进入路基,有利于路基稳定,而在冬季则阻止路基热量的对外散发,不利于路基稳定;暖季施工的隔热板路基在建成初期稳定性相对较差,后期其冻土保护效果显著。

Study on Working Mechanism of Embankment with Insulation in Permafrost Regions

Nonlinear finite element method(FEM) was adopted in the numerical simulation of thermal field characteristic of embankment with insulation in permafrost regions,and the working mechanism was analyzed.FEM analysis results show that,after being embedded with insulation,the thermal field distribution of embankment was influenced greatly,heat exchange between soil under the insulation and external environment decrease greatly,the response speed to the external temperature variation reduced significantly.In different seasons,the insulation has different effect on the permafrost.In summer,it can prevent external heat from entering into the embankment,which is beneficial to embankment stability,while in winter,it can also prevent embankment from cooling,which is detrimental to the embankment stability. For insulation embankment constructed in warm seasons,its thermal stability is relatively poor in the early stage of service and become remarkable later on.