Abstract According to mechanism,characterization and law of rockburst evolution process,a three-step strategy to control rockburst was firstly proposed. It includes the first step to optimize excavation schemes to reduce concentration of stress and energy induced by the excavation;the second step to pre-release and transfer energy concentration;and the third step to absorb energy stored in rock mass by designing reasonable rockbolts and other support types. And then a dynamic control method of rockburst evolution process is proposed. During the construction,the real-time microseismicity monitoring is used to perform warning of rockburst. The feedback analysis and dynamic control strategy if needed can be conducted to perform the three-step control strategy of rockburst evolution process. The proposed method has been successfully used in Jinping II deep headrace and water drainage tunnels with depths of 1 900–2 525 m. The practice verified the applicability of the proposed method.
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Received: 23 May 2012
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