Self Drilling Rock Bolt Is Easy to Reinforce Weak and Broken Rock In Tunnel

by Simone S. sinorockco

Weak and broken surrounding rocks are often encountered during construction in tunnel engineering. Due to the nature of the rock mass itself, the weak and broken surrounding rock is easy to collapse and difficult to form holes, and it is difficult for ordinary bolts to support. Sinorock recommends using the self-drilling hollow rock bolt in tunnel support.

The self-drilling hollow rock bolt system is composed of a hollow anchor bar, coupler, nut, drill bit, plate, and centralizer. It can combine drilling, grouting, and anchoring in one process. The self-drilling anchor bolt system is safe, efficient, and convenient. It is suitable for broken rock, loose soil, and geological conditions where is difficult to drill holes. It helps to ensure the anchoring effect in complex ground conditions and achieve the best construction result.

Self-drilling hollow rock bolt systems are divided into R thread and T thread systems. The sizes of our self-drilling anchor bolt include R25, R32, R38, R51, T30, T40, T52, T73, T76, T103, T111, T127, T130, T150, and T200. We can choose different product sizes and types of self-drilling anchor systems according to different engineering requirements.

Self-drilling hollow rock bolt system, which combines drilling, grouting, and anchoring together, is suitable for broken rock and conditions which are difficult to drill holes. Casing pipe is omitted in construction, which greatly improves construction efficiency.

2. Self-drilling anchor bolt system has a rich variety of drill bits, and the drill bit can be selected according to the properties of rock and soil, which can improve the drilling efficiency.

Self-drilling hollow rock bolt system can fill cracks, consolidate rock mass and soil layer through pressure grouting, and has good grouting spreading radius and reliable anchoring quality.

The hollow bar can be cut arbitrarily and lengthened by the coupler. Therefore, the self-drilling anchor bolt is suitable for construction in the narrow space that the large equipment cannot enter.

During the construction process, the project management team adhered to the principles of short footage, weak blasting, strong support, early closure, and frequent measurement to organize the construction, and made full use of advanced geological forecasts to reinforce the surrounding rock in the cave in advance and strengthen the initial support.

When the tunnel passes through the weak and broken surrounding rock, the excavation disturbance will cause large deformation of the surrounding rock. If the initial support is not timely, the deformation of the surrounding rock may exceed its allowable range, and in severe cases, it will cause the instability of the face and the collapse of the tunnel, resulting in major economic losses. At this time, it is necessary to adopt the tunnel's advanced support measures to control the deformation of the surrounding rock, so as to achieve the purpose of ensuring the safety of the tunnel construction.

Self-drilling hollow rock bolt is an irreplaceable product for tunnel advance support, and plays a major role in geotechnical support:

Radially consolidating the tunnel circumference and supporting the rock mass, forming a load-bearing ring, allowing the rock mass to support itself (with shotcrete and other surface elements).

Umbrella shelters and advance braces are used as means of advance support in the case of inferior rock formations, shallow soil layers, and ultimate stress.

Reinforcement of end faces maintaining internal rock stress for tunneling of large cross-sectional areas.

Locking piles for transferring pressure loads.