| With the gradual advance in highway network planning of The Western Region of China, more highways through the mountains were put into the planning, design and construction phases. Route selection of highway is subjected to terrain constraints, use in the form of deep buried and long tunnels through the mountains usually. As a kind of hard to predict and has larger destructive phenomena of deep rock mass mechanics, rock burst is the unavoidable problem in the process of runnel construction.This paper based on Er Lang Shan Tunnel of YaKang Highway.The tunnel is about 13.4km long, maximum depth of 1500m, is major controlling engineering of YaKang Highway. Thinking of the high in-situ stress level of Er Lang Shan Tunnel site area, covering Layered sedimentary rocks and magmatic rocks, etc, this paper studies the issues related to rock burst, the main research contents and achievements include the following four aspects:1. Considering Layered Rock occurrence and mechanical characteristics, through the analysis of the research methods such as the 71 tunnel rock burst situation both at home and abroad, the main influence factors of rock burst in layered rock tunnel was given. Through preparation process of rock burst after excavation of the tunnel, the mechanism of layered rock burst in surrounding rock qualitative description was given, and using the theory of elasticity cave walls surrounding rock mechanics analysis, the critical stress was given;2. Through numerical simulation of 3DEC, using comprehensive geological analysis, rock burst strength criterion such as the width position for each milestone of project period of rock burst prediction; Combining with layered sedimentary rocks and magmatic rocks of Er Lang Shan Tunnel surrounding rock conditions, compared with the rock burst situation, put forward rock burst prediction and intensity criteria for the classification for Er Lang Shan Tunnel and Similar projects;3. Considering the actual characteristics of rock burst, through numerical simulation of 3DEC, influence law of rock burst space characteristics about Layered rock occurrence, Such as obliquity, orientation, layer thicknesswas given, the delayed rockburst standard of Er Lang Shan Tunnel was given, the causes and laws of the delayed rockburst was analyzed;4. Summarized existing rock burst prevention and control measures applicable conditions, prevention principle and effect, most suitable and effective measures of each part of the constraints and the width was recommended; according to rock burst prediction results and the actual situation of Er Lang Shan Tunnel, rock burst prevention and control of the process and measures was given.Paper work to ensure that Er Lang Shan Tunnel rock burst prediction and mileage of rock burst period of the construction safety, provide a reference for the rock burst research of similar tunnel engineering in the future. |
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