The Experimental Calculation of the Additional Rate for the Ballast During the Railway Construction

Ballast was carried and distributed from the rock mountain to construction site on the basis of the volume on the loose state, and it is needed that some extra amount of ballast added to the design amount of ballast because the volume of ballast densely compacted by tamping machine should be reduced. The standard of the grading, hardness and wear of ballast for high speed railway is strengthened compared with those of the conventional railway differently. But it has not been measured the additional rate for ballast required in the new built line quantitatively and normally designed with reference to cases of the conventional railway. In addition, ballast for the conventional railway has been reflected the historical experiences and so on uniformly. Therefore, this study constructed the test track to calculate quantitatively the correct amount of decreased ballast for high speed railway construction due to the compaction of ballast, analyse the test result, and then suggest the appropriate additional rate of ballast.