It was concluded that,for B type filling material,the compaction indices for the bottom of subgrade bed were catered for the requirement coded in the existing standard once the average vibration acceleration was higher than 3 m/s2.

Research purposes:The experiments are done on the possibility whether the natural filling materials Group B can substitute for the improved filling materials Group B in filling the stone embankment of railway passenger dedicated line.

By mixing bark,wood chip,peat,keramics and charcoal with matured chicken manure compost as media of biofilter respectively,the impact of media assemblage on odor removal efficiency of biofilter was researched at media height of 50 cm and gas detention time of 68.

The results showed that,adding combined packing could enhance the nitrific-ation performance of the system,and reducing sludge age to some extent was propitious to improve the phosphorus removal efficiency.

Experiment on population removal capacity of the new constructed wetland composed with combined packing,Canna,Margaryamelanoide and Misgurnusanguillicaudatus Cantor was conducted.

A new-style combined packing was developed.

This paper briefly introduces the construction method of filling subgrade with high moisture content D group filler improved by mixing, when the coastal railway subgrade filler can t meet the requirements of code for design on subgrade of railway.