Rock bolting system applied for Huafu Highway Tunnel

Effective support technology is a critical issue in front slope protection and tunnel construction. It is very necessary to popularize and apply a new anchor system which is simple to operate and high anchoring quality.

The rock bolting system has the functions of drilling, grouting and anchoring. It’s a kind of advanced anchor system, which can solve the collapse problem when drilling hole by the ordinary bolt and ensure the grouting effect under the complicated geological conditions. It’s obviously superior to the ordinary bolt of the same cross-sectional area in bending, shear strength and surface bonding aspects. Rock bolts can be arbitrarily cut, jointed, prestressed and load release, and can be used as grouting pipe. It has a great application value.

The front slope geological condition of Huafu highway Wayao Bay Tunnel entrance is poor and the soft cover layer is thick. A disturbance will cause landslide when slope cutting. The rainy weather increased the landslide, which makes the slope stability more pore. Ordinary mortar anchor can not take root in the soft slope and is difficult to play a supporting role.

Because the geological condition of the front slope is poor and the cover layer is thick and weathered seriously, if using the ordinary mortar for anchoring and shotcreting, it’ll be difficult to reach the expected effect. If using the long cable for anchoring the mountain, the cost is too high and the construction is very difficult. Therefore, after consideration, combing R32N self drilling rock bolt, steel mesh and shotcrete to protect the slope, which has a great supporting effect eventually.