However, restricted by the narrow terrain conditions in western China, most of these projects need a large-scale excavation of underground caverns to create space for the arrangement of hydraulic structures.
Examine 2d horseshoe excavation full#
To take full advantage of hydropower in Southwest China, a large number of hydropower stations have been constructed. Finally, a relationship between the average value of the local energy release rate and the rockburst intensity was established to assess the risk of rockburst induced by the blasting excavation of a deep tunnel. Thus, the shorter the distance to the tunnel wall the bigger and more intense the energy release. The first decrease of strain energy results from elastic unloading waves and does not cause brittle failure in rock masses, which is consistent with the elastic condition but the secondary reduction of strain energy is because the accumulated strain energy in rock masses exceeds the storage limit, which will inevitably trigger the brittle failure in the rock mass. Studies have shown that, due to transient unloading, the strain energy of the surrounding rock mass goes through a dynamic process of decreasing at first, increasing second, then reducing before finally stabilizing. The brittle-ductile-plastic (BDP) transition property of Jinping marble was numerically described by the Hoek-Brown strength criterion, and the dynamic energy release process derived from the transient unloading of in-situ stress was studied using an index, local energy release rate. This research discusses rockbursts that happened during the construction of a diversion tunnel at Jinping II hydropower station. Previous studies have examined the unloading of in-situ stress resulting from deep tunnel excavation as a quasi-static process but the transient stress variation during excavation has received less attention. 4China Gezhouba Group Explosive Co.Ltd, Chongqing, ChinaĪs a man-made engineering hazard, it is widely accepted that the rockbursts are the result of energy release.3Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education, China Three Gorges University, Yichang, China.2Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering, Ministry of Education, Wuhan University, Wuhan, China.1Hubei Key Laboratory of Construction and Management in Hydropower Engineering, China Three Gorges University, Yichang, China.
Yong Fan 1,2,3, Xianze Cui 1, Zhendong Leng 1,4, Junwei Zheng 1*, Feng Wang 1 and Xiaole Xu 1
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