| Taking left tunnel of West Qinling on Lanzhou-Chongqing railway as the engineering background,the analytical investigationon is conducted on how to ensure the quick tunneling of TBM in terms of TBM no-load stepping mode and supporting infrastructure construction,continuous conveyor belt slag tapping adapting to tunneling speed,eliminating mutual interference between continuous slag tapping system and secondary lining construction,TBM maintenance and details transformation.Through scheme comparison,TBM no-load stepping uses cylinder propulsion,and cambered slipway scheme.This scheme needs to complete the construction of preparatory hole 2113 m arc stepping track in 2 months of TBM assembly outside tunnel.Because stepping scheme uses the frictional force of arc steel plate and arc stepping slide as the reactive force to promote the cutter assembly to advance,arc stepping slide is required to have good forming quality.In order to meet the double requirements of TBM stepping on arc stepping slide construction speed and construction quality,the sliding mode construction technology is introduced,to achieve the intended target better.In order to guarantee slag tapping ability of continuous conveyor belt matching TBM tunneling speed,continuous belt conveyor is adopted to pass through the whole construction site at the first tunneling stage,and the slag is directly conveyed to temporary abandoned slag field by means of continuous slag separating device separated loading;After the main tunnel conveyor belt conveys the waste slag to inclined fork,the waste slag is transported to the tunnel through the conveyor belt,and the waste slag is directly transferred to abandoned slag field through the mountain climbing conveyor belt at the second tunneling stage.To ensure the safe operation of mountain climbing conveyor belt,the conveyor belt bracket is tested through the software,and the testing result shows that the design is safe and feasible.In view of the contradiction of continuous slag tapping conveyor belt system and traditional secondary lining construction method,lining trolley and rack are designed to meet the walk-through needs of the rail transit vehicle and conveyor belt.The practice proves that the designed lining trolley and lining rack solve the problem of synchronized implementation of slag tabbing and lining construction.In addition,this paper proposes TBM daily maintenance measures and cutter transformation,continuous conveyor control system transformation and other details details transformation measures against some actual site problems encountered during the construction.These measures guarantee the smooth tunneling of TBM better,and good social benefits and economic benefits are obtained while the quality and schedule are ensured. |
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