ABSTRACT:

This paper covers progress report of the study on the development process of rock bursts in underground hard rock engineering. It introduces real-time monitoring techniques including microseismicity, digital borehole televiewer, wave velocity and deformation for evolution process of rock burst during the excavation of underground hard rock engineering. A new numerical method called continuum-discontinuum cellular automation method has been developed to show evolution of energy, stress, displacement and microseismitity during evolution process of rock burst during the excavation of underground hard rock engineering. The dynamic warning methods have been developed to warn type, location, zone and intensity of rock burst. The dynamic control techniques such as optimization of excavation size, dynamic determining advancing rate, energy absorbing reinforcement, etc. have been devoloped to change evolution process of rock burst during the excavation of underground hard rock engineering to reduce risk of rock burst. The related techniques have been applied in China Jinping Deep Underground Research Laboratory, which has an overburden of 2375 m with 14 m diameter of tunnels, and in Jinping II hydropower station, China, which has four headrace tunnels and one water drainage tunnel with overburden of 1900–2500 m.

1 INTRODUCTION

Rock bursting is a common phenomenon occurred during the excavation of underground hard rock engineering projects (Zhang etal. 2012a, Fengetal. 2013). It occurred in tunnels at Jinping II hydropower station in China, Neelum-Jhelum project in Pakistan, the Trans-Andean project in Peru and many coal and gold mines in the world. Since long time ago, a lot of efforts have been taken to monitor, assess, warn and mitigate risk of rock bursts. The research group of the author has also concentrated to mitigate risk of rock bursts since 1996. This paper reviews the recent progresses in this field conducted by this group.

2 TYPES, KEY FEATURES AND INTENSITIES OF ROCK BURST
2.1 Types of rock bursts
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