Abstract：
Based on construction practices, this paper introduces the treatment method for clearance-intrusion induced by primary support in a soft rock railway tunnel with large deformation in abroad. By means of intensive monitoring and measurement, heavy support measures were taken to treat against increasing deformation, including a secondary shotcrete layer, system bolts, feet-locked bolts, a temporary lateral steel brace, and temporary inverts. As for the clearance-intrusion section, the original primary support layer was dug out through trapezoidal grooves after reinforcement with a lateral steel brace. Then, the new primary support and waterproofing sheet was installed, followed by pouring the reinforced concrete ribs and secondary concrete lining. It is shown that this treatment method of combining a permanent lining with a temporary support is simple, safe, cost-effective, and relatively quick.
2013, Vol. 50 