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Abstract Based on field testing of blasting vibration，the blasting seismic wave propagation laws in underground diversion tunnels under complicated construction conditions are studied. Regression analysis of testing data is conducted according to Sadaovsky empirical formula and the field testing results indicate that horizontal particle peak velocity of blasting vibration can be taken as safety criterion for underground chambers. The numerical simulation is carried out to study the influence of blasting vibration on adjacent diversion tunnels by software the fast Lagrangian analysis of continua in 3D(FLAC3D) and distributions of particle vibration velocity，stress and displacement of the adjacent diversion tunnel wall are obtained. The stability of adjacent chamber is assessed by considering the effect of static load and dynamic load separately. The result of numerical simulation shows that the blasting vibration responses predicted by numerical simulation agree well with field testing；and it is reasonable to use blasting vibration velocity as safety criterion. The near-blasting side of adjacent tunnel is the area where failure tends to occur under blasting load；and the tensile failure will appear possibly in adjacent tunnel straight wall facing blasting with the blasting impact load increasing. Finally，the critical vibration velocity of adjacent chamber under blasting vibration is proposed according to the statistical relationship between maximum tensile stress and maximum vibration velocity combined with the dynamic tensile strength criteria of rock for a project.
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Received: 10 August 2009
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