Applications in the construction of high-speed railway tunnels in mountainous area

- May 05, 2019-

With the increase of national high-speed railway construction, high-speed rail in many places still has to pass through the mountainous area. The  cement mortar sprayer is used as the anchor spray support equipment for the initial construction of the high-speed railway tunnel in the mountainous area. The development of the national high-speed rail construction of the shotcrete machine plays a vital role. So what is the specific role of the shotcrete in the construction of high-speed railway tunnels in mountainous areas?

double cement mortar sprayer-001The cement mortar sprayer is used as the professional equipment for anchoring and spraying. In the early stage of mountain tunnel, bolting and spraying support can quickly control or limit the loosening deformation of surrounding rock, and give full play to the bearing capacity of surrounding rock. It is an important link in the construction of “New Austrian Law”.  The spray anchor support of the cement mortar sprayer is implemented in the order of the rear side wall of the first arch. Initial support includes system anchors, steel frames, steel mesh, and spray rafts. The initial support is followed by the excavation face in time to reduce the exposure time of the surrounding rock, inhibit the displacement of the surrounding rock, and prevent the surrounding rock from loosening in a short period of time. When the shotcrete machine is working, the concrete is generally stirred outside the hole, and the concrete is transported into the hole through the concrete transport vehicle, and the air compressor supplies air. The combination of tidal spray and wet spray, the amount of one shot of the surrounding rock is not large, and the squirting technique is adopted. The quality requirements and specifications of the tidal spray are relatively low, easy to operate, but the dust is large, and the quality of the concrete is lower than that of the wet spray. In the broken section of surrounding rock, it is required to use a large amount of spray, large thickness, high quality of concrete, fast formation of strength and good support effect. Wet sneeze technique should be adopted. Both injection methods are fed by the outside of the hole. The anchor is drilled with a trolley and uses a medicine roll anchor. The medicine roll anchor is easier to operate than the mortar anchor, and the quality of the anchor can be ensured, and the strength is increased quickly, so that the anchor can act in time and force. In the construction of bolting and shotcreting support for mountain tunnels, the shotcrete machine can perfectly complete the initial support tasks of the tunnel under the cooperation of the drilling rig, ensuring the smooth progress of the construction work in the later stage of the tunnel.