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Aiming at the poor geological conditions of water conveyance tunnel in Lanzhou water source construction engineering by double shield TBM excavation, the comprehensive methods and treatments were put forward by data statistics, engineering analogies, and other methods. Before TBM tunneling, F, fault zone and F, fault zone were excavated by drilling and blasting method. After initial support which guaranteed the stability of surrounding rock, TBM slided through and installed segments. Based on geological analysis along tunnel, combination the observation of tunneling face, rock muck analysis and tunneling parameter analysis, the geological conditions of surrounding rock in front of tunneling face were comprehensively predicted by using three-dimension seismic method and three-dimensional resistivity method. The principle of " drainage first, drainage and plugging combined" was adopted, the variable slope drainage system was established, the operation mode of the drainage system was determined according to the amount of water gushing. According to the characteristics of the front shield blocked, the method of releasing surrounding rock pressure by manual excavation of the heading tunnel from the telescopic shield was adopted to make the TBM out of blocked. Based on identifying geological conditions, the use of chemical grouting and cement grouting consolidation broken surrounding rock, controlling TBM tunneling parameters, slow tunneling through the fracture zone. TBM tunnneling practice shows that the adopted technology is effective and the poor geological conditions have not caused serious consequences for TBM. [ABSTRACT FROM AUTHOR]

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