ABSTRACT
The base structure in heavy-haul railway tunnels is greatly affected by the train load, which leads to a much higher rate of basal structure disease compared with that of an ordinary tunnel. In this paper, two different axle loads of a heavy-haul train, 270 and 300 kN, are set as the research objects, and calculations for the additional load on the surface of the basement structure, including the ballast, invert arc filling, invert arc and rock, caused by a heavy-haul train in single and double lines when the classifications of the surrounding rock are III, IV and V are carried out. These calculations are all based on existing domestic specifications, research results and the layered elastic theory. In addition to the theoretical calculations, research methods including a field-embedded optical fibre grating sensor, large vibration test and real-time remote monitoring have been applied to obtain measurements that could verify the calculation. According to the study results, taking each type of rock and axle load condition into consideration, the calculations and measurements reveal that the maximal additional dynamic loads on the heavy-haul railway appear in the vertical direction of the track, and they decrease when the basal structure goes deeper. The study also finds that the surrounding rock level has a great effect on the maximal load and its attenuation in the vertical direction.
Acknowledgement
The constructive comments and suggestions made by the Program of Science and Technology Department of China Railway Corporation (2014G005-A) are acknowledged.
Disclosure statement
No potential conflict of interest was reported by the authors.