多年冻土地区路堤路堑过渡方式试验研究

Study of the Transition Structure from a Cut-Section to a Fill-Section of Roadbed on Permafrost Regions

提出了多年冻土地区路堤、路堑过渡段的结构形式:为保护路基下面多年冻土,在整个过渡段在暖季到来之前铺设保温材料;为了减少地表水的影响,在路肩线以下设置了复合土工膜防渗层;为了保证过渡段低于临界高度部分路基的稳定,对基底进行了换填;为了增加稳定性,在开挖地段设置了台阶并开展了现场实体试验.对采用此过渡形式的青藏铁路北麓河路堤路堑过渡段进行了现场观测和分析,验证了其适应性.

In this paper, a transition structure from cut to fill of roadbed on permafrost regions is presented： a thermal-isolation layer is paved before the warm season in the transition section; a water resistant layer of non-woven textile is setup to avoid water influence; for those parts of the transition where the roadbed height is lower than a critical height, the original ground must be replaced with well-graded large size soils to keep the roadbed stability. Observation for the thermal regime and the deformation of an experimental transition section with the presented structure in the Qinghai-Tibet Railway is conducted for 3 years. Based on the observation, the performance of the cut-fill transition structure is analyzed.