Abstract: To investigate the timevarying pattern of the properties of grout body (rock slaghard slurry) prepared by replacing commercial sand with waste rock slag for grouting behind lining and its influence on ground settlement, a consolidation test is conducted using a selfmade consolidation device. Thus, the timevarying pattern of properties, such as elastic modulus of slurry, is determined. The FLAC3D finite element numerical simulation is performed for the influence of rock slaghard slurry on ground settlement. The results reveal the following: (1) Once the consolidation of rock slaghard slurry is completed, the properties of the slurry undergo rapid development. The initial elastic modulus is in the range of 11.4 MPa and reaches 120160 MPa after 3 d. The internal friction angle and cohesion increase by 21.8% and become 45 times compared to corresponding values when the consolidation is completed. (2) Compared with conventional hard slurry, the rock slaghard slurry used for grouting behind lining effectively reduces ground settlement with a maximum reduction of 20%. The difference in the properties of the slurry after consolidation does not change the lateral influence range of ground settlement. (3) Field measurement data reveal that the simulation results can accurately reflect the ground settlement pattern induced by grouting behind lining using rock slaghard slurry, confirming the effectiveness of rock slaghard slurry in controlling ground settlement.

Key words: largediameter slurry shield, waste rock slag, grouting behind lining, consolidation test, ground settlement, numerical simulation