多年冻土地区构筑物沉降变形分析

根据现场观测和数值分析，将多年冻土地区构筑物的沉降变形归结为几个具有不同机制的物理力学过程共同作用所致。伴随着冻土上限下降所产生的融沉，由于构筑物的修建引起多年冻土层升温而产生的高温冻土的蠕变和活动层的未冻土在暖季发生的蠕变，以及由于活动层中冻融循环改变了土的工程性质而导致的附加沉降变形。基于青藏公路和青藏铁路的修建和维护的实践，分析了以上几个可能引起沉降的原因。

Analysis of settlements of constructions in permafrost regions

Settlement of a construction in permafrost regions results from several simultaneous processes, each with a different mechanism. The first is thaw settlement due to the degradation of the permafrost underneath. The second is creep, including creep of warm frozen layers and creep of unfrozen soil in the active layer in warm seasons. Third, because freeze-thaw cycling in the active layer can change soil properties; extra settlement would also take place in the first years. These three processes are interactive, which makes any single attempt of calculation very difficult. Based on field investigations and practice of construction and maintenance of Qinghai-Tibet railway and highway, these three processes were analyzed previously.