热力交互作用下冻土路基融化沉降分析

基于大变形融化固结理论建立了多路基结构相互作用融化沉降数值模拟平台,并研究了公路和铁路路基不同相邻间距条件下的融化沉降规律.通过分析计算结果表明,过近的路基相邻间距会加速下覆冻土层的融化.随着相邻间距的增加,两种路基间热学场的影响将逐渐减弱.对于相邻间距较近的情况,路基变形场相对于路基中心的不对称性随时间持续增大.随着路基相邻间距的增大,变形场的不对称性发展逐渐减弱.根据本文的计算算例,当两种路基间距大于20m时,不同路基间的热学和力学场之间将不会产生显著的相互叠加影响.因此,建议在多年冻土区构筑物密集修建地区,构筑物间的安全修筑距离应大于20m.

Analysis on the Thaw Settlement of Permafrost Embankment Under Thermal and Mechanical Interaction

Based on the large strain thaw consolidation theory,a numerical simulation platform of multi-infrastructures interaction was established,and the law of thaw settlement of highway and railway embankments at different adjacent horizontal spaces was studied.According to the analysis of calculated results,it was indicated that too close spacing of adjacent embankments will accelerate the thawing of the underlain permafrost layer.With the increase of adjacent spacing,the interactions of thermal fields between two embankments decrease.For the case of closer adjacent space,the asymmetry of the embankment deformation field referring to the center of the pavement increases with time.With the increase of adjacent space,the asymmetry of deformation field disappears gradually.According to the case study in this paper,when the adjacent space is larger than 20 m,there is no notable superposition interaction influence between the thermal and mechanical fields of different embankments.Therefore,it is suggested that in the areas infrastructures intensively constructed,the safety distance between the structures must be larger than 20 m.