Nowadays, a broad range of versatile innovative methods and systems is available, allowing efficient and safe underground excavation works. Generally speaking, the development of efficient self-drilling anchor bar in underground mining and tunneling came along with the major developments and improvements in the field of rock drilling technology which took place in the 70’s and 80’s of the last century.
In the 1980’s, different types of self-drilling anchor bar have been developed and consequently enhanced, as shown by different patent applications dating back in these days. In conjunction with further improvements in rock drilling technology, self drilling hollow bar became widely popular in the 1990’s and represent a commonly used rock reinforcement element in modern tunneling. In the past decade, various other self-drilling anchor bars have been developed both for mining and tunneling applications.
Conventional pre-support methods, such as wooden or iron ram spiles or forepoling boards, have been known as a two-step operational system which stands for separate drilling and tube installation while self drilling anchor bar combines them together. Self drilling anchor bolt has two performance: drilling and grouting. It features a hollow bore for flushing, or simultaneous drilling and grouting.
As an efficient anchoring method, self drilling anchor bar is mainly used for slope stabilization, foundation with micropiles and tunneling, it’s also widely used in the railway system, metro project, etc. It can be installed in sites with weak rocks, loose soil, weathered layer, sand with stone layer and so difficult to create a hole in complex formation. The unconsolidated ground condition favor the self drilling anchor bar technique for fast and simple method of installed compared to the traditional method. In modern tunnelling, especially in subsidence-sensitive or urban areas, the usage of self-drilling pipe umbrella support is a widely and successfully adapted spacious pre-support system.
No.1703, Building 3, No. 1 Fenghua Road,High-tech,District , Luoyang , China (Henan)Pilot Free Trade Zone, Henan Province, P.R. China.