Abstract: The tunnel from DK278+824 to DK279+389 on BeijingShijiazhuang railway is a triplearch tunnel, with the tunnel tubes being at different altitudes. The loading conditions of the triplearch tunnel are analyzed and the causes and features of the deformation of the triplearch tunnel are studied. The results show that, due to the overburden pressure and the lateral soil pressure, the lining of the tunnel tube at higher altitude tends to turn in anticlockwise direction; the vertical displacement of the lining of the tunnel tube at higher altitude can be brought under effective control by means of backfilling rubble concrete at the tunnel floor. The numerical simulation proves that the displacement control technology is feasible. 

Key words: different altitude, triplearch tunnel, lining, deformation, loading, numerical simulation