Substantiation of the seismically safe mass of the group of drill charges during explosive works on the construction of metro tunnels

Abstract

The purpose of the work is the development of earthquake-safe conditions for drilling and blasting during tunneling in tunnels and shafts that will ensure the maximum speed of construction of the subway in the city of Dnipro. Research methods. For decision-making, methods were used to analyze the patterns of seismic wave propagation in various rocks and their effect on buildings and structures. Field studies with the transfer of results to existing mine workings. The rationale for a seismic safe mass of groups of blast holes during blasting operations in the construction of the subway tunnels in the city of Dnipro was developed on the basis of current regulatory documents [1 ÷ 5] and contains basic recommendations on the organization and technology of monitoring seismic vibrations of soil at the foundations of buildings and structures in the zone of influence of explosive works. The results. A technique has been developed for determining the coefficient (K) depending on the conditions of the explosion based on experimental explosions for instrumental measurement of the speed of seismic vibrations of soil at the base of the foundations of buildings and structures for specific explosion conditions. Theoretical calculations are given of the maximum permissible mass of charge groups depending on the conditions of the explosion and the distance to buildings and structures. Special seismic-safe parameters of drilling and blasting operations have been developed that will ensure the maximum speed of excavation of mine workings. Scientific novelty. Modeling the predicted speed of seismic vibrations of the soil allows you to optimize the parameters of the hole charges, which will reduce the seismic load on buildings and structures and improve the quality of blasting. The methodology for determining the coefficient (K) depending on the conditions of the explosion allows you to most accurately predict the parameters of seismic oscillations at a distance from the place of the explosion. The practical significance. The adequacy of the predictive estimate of the speed of seismic vibrations of the soil at the base of buildings and structures has been experimentally proved, depending on the mass of charges and the conditions of their blasting on the efficiency of drilling and blasting, which will increase the rate of excavation during the construction of the subway in the Dnieper.