岛状冻土路基侧向位移地温响应数值模拟分析

Numerical Simulation Analysis on Lateral Displacement Response of Patchy Permafrost Subgrade along with Ground Temperature

在多年岛状冻土区由于地温环境的变化,导致公路路基为达到新的热稳定状态而不断发生自适应结构变形。当路基的侧向变形过大时,就会引发边坡滑塌、纵向开裂等严重的路基病害,从而直接影响公路的使用安全。掌握该类路基侧向位移的地温响应规律是提高公路设计质量的基础前提,因此,文中以实际工程为依托,采用有限元数值模拟的方法,对工后一年内的路基侧向位移进行了瞬态模拟分析,通过现场实测对比,提出了高纬度地区多年岛状冻土路基侧向位移的年周期性地温响应过程可分为冻结、过渡和融化3个阶段,并根据数值模拟结果,揭示了各阶段路基侧向位移的地温响应特征。

The adaptive structural deformation has been produced to make a new thermal stability of highway subgrade in patchy permafrost areas,which is caused by the changes of ground temperature environment,while under a given large deformation,it brings about a series of serious subgrade diseases such as slope sliding,longitudinal cracking and so on,so it affects the driving safety directly.Mastering the response laws of lateral displacement along with ground temperature is the basic premise of improving design quality for this highway,so based on the practical project,in this paper the transient process of lateral displacement is simulated and analyzedby finite element numerical simulation during one year after the project is completed,and after comparisons with the in-situ data,the results shows that the annual cyclical response process of lateral displacement along with ground temperature can be divided into three stages:freezing period,transition period and thawing period for the patchy permafrost subgrade in high latitudes,and then based on the numerical simulation results,the study presents the response characteristics of lateral displacement along with the ground temperature for each stage.