Abstract:

Heaving and settlement occur to the track bed of a running Metro tunnel, which has been in service for almost 2 years. In the paper, the causes and countermeasures for the heaving of the track bed are analyzed. It is concluded that there is a gap between the track bed cushion layer and the invert filling layer, the water at the gap results in pressure and causes the track bed heaving. Countermeasures, including water releasing and pressure reducing by means of borehole drilling, gap filling by means of grouting, reinforcing track bed, lining and surrounding rock by means of tie bolting, are taken. In the end, good treatment effect has been achieved.

Key words: Metro, slab track bed, heaving, drainage, grouting, tie bar