| Based on the construction of the first phase of Qingdao metro line Line 1,under the condition of strict safety control standard of blasting vibration,in order to reduce the disturbance of blasting vibration and improve construction efficiency,the vibration reduction technology of three projects of shaft,station main body and TMB dismantling hole(interval)is studied respectively.On the basis of field test and monitoring to obtain effective vibration data,this paper respectively studies the technology of breaking rock phase transformation of carbon dioxide,the rock breaking technology of Static crusher,the technology of hollow hole damping and the construction technology based on multistage wedge cutting "guide hole+reserved Light blasting layer",Through numerical simulation,the influence of continuous spacing arrangement and initiation mode of auxiliary eye on vibration velocity is analyzed,and the method of grey correlation analysis is combined with MATLAB software programming to deal with the measured data,and the importance of influencing factors of blasting vibration intensity of tunnel controlled blasting is sorted.Through the above research,we draw the following conclusions:(1)Through the regression of the blasting attenuation coefficient k and a,the comparison and analysis of the carbon dioxide blasting technology and the blasting vibration velocity of explosive are carried out,and the vibration velocity caused by the explosive is 5%-10%.At the same time,using the theoretical calculation to compare the carbon dioxide blasting technology and the stress of explosive blasting,the rock stress wave produced by explosive blasting is 15 times times of the 73rd CO2 expansion tube,and it is more easy to control the blasting harm.(2)The core parameters,such as static hole spacing,are obtained by theoretical calculation,and the construction scheme of static crusher in free surface construction is tested.(2)Through numerical simulation,the paper analyzes the parameters of hollow hole and enlarged groove eye in the seven-hole excavation of hard rock geology,and tests the feasibility of single ring blasting vibration reduction technology of hollow hole single sound in extreme condition,and controls the vibration speed within 0.5cm/s.(3)Through the study of multistage wedge cutting parameters:three-grade wedge-shaped notch,four-stage wedge cut more than two-stage wedge-shaped cutting blasting vibration velocity is significantly reduced,the notch angle from the lower level to the advanced,the hole dip in order to effectively reduce the rock clip production to achieve damping effect.(4)Through the numerical simulation of the same section auxiliary eye continuous or spacing arrangement to:two holes in the same segment of the auxiliary eye Continuous spacing arrangement for the same point of the maximum blasting vibration speed does not have an impact;continuous layout initiation when the vibration velocity attenuation faster,to the protected buildings caused by less sustained damage,However,the blasting vibration velocity attenuation is slow when the interval is disposed,and the sustained damage to the protected building is relatively large.The initiation mode of the maximum vibration velocity from a single point initiation to a small one is:center initiation,forward initiation and reverse initiation.(5)In view of the many factors of controlling blasting,taking the characteristics of not strong directional vibration control measures,using the grey relational degree analysis method,combining with MATLAB programming calculation,taking hollow hole cutting as an example to quantify the importance of each influencing factor on the blasting strength and sorting. |
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