Railway roadbed ventilation,as a positive roadbed cooling technique,has attracted much attention from researchers,which can effectively protect the frozen roadbed and maintain the roadbed stability by raising the permafrost table.

The paper briefly discusses the main factors influencing the permafrost table and the main methods of determining the upper limits for the permafrost table in Qinghai-Tibet Plateau.

The change of the permafrost table under asphalt parement is calculated based on heat transfer with phase change using the observation data.

The in-situ monitoring results show that the reasonable embankment height has positive effects on frozen soil protection and can promote the rise of permafrost table under the embankment.

Based on the model test data indoors, combined with the numerical calculations and the measured temperatures of air and permafrost,and the test data of roadbed in Fenghuoshan, the protecting effects of the awning on the permafrost table along the road and railway in permafrost regions are compared.

From a laboratory-modeling test, combined with the air temperature and permafrost temperature data of a field test roadbed in Fenghuoshan, the advantage of riprap slope protection for rising permafrost table along a road or a railway in permafrost regions is shown.

Preparation and mechanical properties of nylon6/rubber/unmodified clay nanocomposites;

To reduce the high cost for preparation of polyamide-6/clay nanocomposites and overcome a decrease in the toughness of the nanocomposites, in this work, we have developed a novel route with low cost to prepare polyamide 6/rubber/unmodified clay nanocomposites.