Quality Control for Excavation of Super Large Underground Powerhouse Caverns at Xiluodu Hydropower Station

The scale of the underground powerhouse caverns in Xiluodu Hydropower Station is the first in China,which are intensive,and have high side wall,large span and more intersections.The discontinous problem is serious because of the inner beddings of the basalt.In order to achieve the high quality,high efficiency and good stability during the caverns excavation,a large number of advanced quality control measures and detection methods are used to strictly control the damage range of rocks in excavation,and ensure the good contour of caverns;Simultaneously,the real time monitoring dynamic analysis feedback system of design,research and construction is established.According to the results of monitoring and inversion analysis,the supporting parameters during excavation are eptimized dynamically.The results show that the greatest deformation of surrounding rocks after excavation is identical with the design value,and the cavern stability is well.Therefore,the summary for the excavation methods and quality control measures of the caverns in Xiluodu Hydropower Station could provide some references for similar projects.