(1. State Key Laboratory of Geomechanics and Geotechinical Engineering，Institute of Rock and Soil Mechanics，Chinese
Academy of Sciences，Wuhan，Hubei 430071，China；2. Yalong River Hydropower Development Company，Ltd.，Chengdu，
Sichuan 610051，China)
Abstract：The Jinping Underground Laboratory(CJPL) in China is currently the world?s deepest laboratory in overburden. The paper focuses on the second phase project of CJPL，namely CJPL–II. Rock mass behaviors during the whole excavation process were real-timely obtained via a comprehensive monitoring approach，including the measurement of deformation and fracturing of rock mass，the elastic wave testing，the distribution stress testing，the micro-seismic and AE monitoring，the 3D laser scanning，the rock mass structure photogrammetry，the rock blasting monitoring，etc. It was also achieved that the multi-scale ruptures，from micro to macro，of rock masses，as well as their deformations from excavation surface to deeper surrounding rock，were detected or monitored. Based on a proposed identification approach of the engineering geology，the geological zones of deep rock mass structure were distinguished，in which rock mass deformation characteristics and their failure modes as well as the deformation and fracturing information prior to rock mass hazards were revealed. Several tunnel hazards including rockbursts and collapses were pre-warned，which ensured the safety during the construction of tunnels. This research with lots of basic data obtained is great significant to safe construction and the long-term operation of CJPL-II and to explore the deep problems of rock mechanics and engineering science.
LI S J，FENG X T，LI Z H，et al. In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels[J]. Science China—Technological Science，2011，54(Supp.1)：167-174.
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2016, Vol. 35 
