The stratum of Nanjing Yangtze River Tunnel is mainly fine sand

of which the grain composition is good. If the excavated fine sand is discharged directly

the environment near the piling position is easily polluted; and it is also resources waste without reuse. Based on the above consideration

the main subject of research is that how the discharged fine sand can be reused in the aspect of back grouting

and after the reuse of the fine sand

the back grouting recipe should be regulated in time with the change of grain compostion of excavated fine sand. The results show that the excavated fine sand can be reused in the back grouting substituted for the purchased sand

which can save money groatly.