| Now,a large number of subway tunnel engineering began to emerge,In the course of tunnel blasting excavation,the vibration and settlement of ground particles caused by the metro tunnel,which can affect the safe use of the adjacent surface buildings in the tunnel blasting excavation area.Therefore,it is important to study the vibration effect of blasting excavation and the safety criterion of multi parameters in the subway tunnel,which is important to ensure the safe use of adjacent surface buildings.The thesis took the grouting method of Pearl River Delta Intercity Rail Transportation to the Foshan section of Guangzhou as an example.Firstly,the primary and secondary influencing factors of vibration velocity are found by grey correlation;Secondly,simulating the change rule of surface subsidence displacement and vibration velocity by the FLAC3 D software;Finally,the vibration reduction measures of this tunnel blasting engineering was recommended.The research results are as follows:(1)Based on the grey correlation degree,the primary-secondary influencing factors of vibration velocity is that: Charge weight > Distance between explosion source and measuring point > Elevation difference > Horizontal distance.(2)During the simulation of tunnel blasting excavation,tunnel excavation has been surface particle vibration velocity in a certain range greater than from the tunnel face and distance before excavation surface particle vibration velocity.(3)In the tunnel excavation process,the monitoring of vertical to direction of tunneling settlement,from the tunnel face to the tunnel excavation zone,the surface subsidence displacement law by the "single peak" form gradually transformed into "double peak" form.(4)A set of vibration reduction system is proposed,the effect of ditch excavation are simulated and calculated.The results show that the most obvious effect of the form of ditch excavation is horizontal distance between ditch and detonation source. |
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