Rapid development of coalmine bolting in China

Despite a slow beginning, coalmine bolting in China has got a rapid development in the past twenty years for pressing demand of deep mining, which has provided a sound technical support for safe and efficient coal production. In terms of technical characteristics, this process can be divided into three stages: "one-high" stage (high strength bolting), "two-high" stage (high strength and high pretension force bolting) and "three-high" stage (combination of high strength, high pretension force and high system stiffness bolting). Studies show that rational match of the "three-high" is safeguard to deal with the increasingly complicated deep mining situation. A whole set of strengthening bolting technology based on the "three-high" is put forward. The feasibility of its application under the most support-challenging condition-retained roadways is well tested by a typical engineering case.