Self-drilling anchors in tunnel surrounding rock support

Self-drilling bolt support in the form of tunnel construction support. It can effectively control rock loosening caused by blasting and excavation and improve the surrounding rock stability. Jiaozhou Bay Subsea Tunnel In Qingdao connection line passes through Yunnan Road and Sichuan Road. It is in a built-up area, surrounded by numerous military and civil facilities and densely distributed pipelines. During the tunnel construction, the safety of the above-ground facilities should be ensured, but the above-ground buildings are mainly multi-layered, which puts forward high requirements on the excavation and support of the surrounding rock.

 

After forming an underground cavern by blasting or other means during construction, the rock's force status has changed, and some surrounding rocks formed a loose circle. The rock's self-stability was very poor in the loose zone, which caused adverse effects for cavern lining structure. To solve these problems, the construction party used self-drilling anchors to reinforce the loose circle and restore stability after releasing the stress.

 

Self-drilling anchors have the following characteristics:

 

1)     Self-drilling anchor bar is made of high-strength steel and continuous-wave thread conform to international standards. Anchor bars can be cut and lengthened on request, and they can be used in a narrow space.

2)     Self-drilling anchors combine drilling, grouting, and anchoring functions, which improves the anchoring efficiency. It does not need to take out after drilling, which solves the problem of hole collapse in unusual geology.

3)     The hole collar plug makes the grouting pressure higher and the slurry fully contacts the rock, which ensures reliable anchoring quality.

4)     Easy installation and good anchoring effect not only improve construction efficiency but also reduce engineering costs.

 

Tunnel support adopted self-drilling anchors, not only effectively controlled the deformation and displacement of the surrounding rock but also greatly the integrity and stability, which provided a guarantee for the tunnel construction smoothly. This project provided a successful experience of using anchoring support in urban tunnels, which was worthy of promotion and application.

 

Sinorock has been focusing on the geotechnical anchoring industry for more than ten years and is an experienced anchoring products manufacturer. As the largest anchor support solution provider in China, Sinorock's vision is to meet customers' needs with professional service, solve problems in the anchor support project, and ensure the project construction smoothly.