Abstract:

 In order to solve the problem of grouting and consolidation of the upper part of the deep backfill, the grouting reinforcement design of the upper backfill was carried out on the basis of theoretical analysis, and the grouting effect was analyzed through numerical simulation. On the one hand, the pores increase the upper load, which has the effect of compaction. On the other hand, it effectively isolates the train's dynamic load from passing down and prevents the backfill from disturbing settlement after construction. In the practice of grouting engineering, the grouting quality control was focused on, and the problem of grouting defects caused by the poor forming of the surrounding grouting wall was solved, and the dense grouting consolidation in the enclosed area was realized. The pulp effect is tested and evaluated. After the upper grouting construction is completed, the surface settlement of the backfill is monitored. The monitoring results show that the method of "Tunnel backfill + Upper grouting reinforcement" is feasible to treat the karst cave and the settlement is controllable.

Key words:

railway tunnel, giant karst cave, backfill of cavern, upper grouting reinforcement, grouting control technology