Study On The Influence Law Of Blasting Vibration Of Underground Oil Storage Cavern On Adjacent Roadway

As an oil storage facility,the safety and stability of the underground oil storage cavern directly affects the effect of oil storage,and the construction method of the underground cavern greatly affects the safety and stability of the structure.Drilling and blasting method is the main construction method for the construction of underground oil storage caverns.During the blasting construction of oil storage caverns,the blasting effect will produce severe vibration.The vibration load will act on the main cavern and the existing roadway structure.Under the action of blasting vibration,the original micro-cracks and other meso-structural defects in the surrounding rock will expand to form macro-cracks and form cumulative damage.The cavern structure will produce engineering safety problems such as surrounding rock loosening,cracks,and increased water seepage rate,which will seriously affect the safety of the construction roadway and the existing cavern structure.Therefore,it is of great practical significance and practical significance to study the safety of blasting vibration on the construction roadway and the existing cavern structure and initial support.Based on this,this paper relies on a large-scale water-sealed cavern project in southwest China.Through theoretical analysis,field monitoring and numerical simulation,the influence of blasting vibration on the vibration velocity and tensile stress of the main cavern and the existing roadway is analyzed.The concrete bolting and shotcrete support scheme is proposed to strengthen the roadway structure and ensure the safety and stability of the structure.The basic theory of blasting vibration and the transmission attenuation law of vibration wave are expounded,and the theoretical analysis model is established to obtain the relationship between primary support and surrounding rock deformation.According to the blasting vibration data monitored on site,the influence of blasting vibration on the existing cavern structure is analyzed in detail.The regression analysis of the vibration data is carried out to obtain the Sadaovsk empirical attenuation formula,which can be used to predict the blasting vibration velocity.Through the analysis of the vibration data,it is considered that the blasting vibration has the greatest influence on the vertical direction of the tunnel structure,and the deformation and failure in this direction should be focused on during the blasting operation.Through the numerical simulation of GTS NX finite element software,the vibration velocity and tensile stress of the main cavern blasting on the connecting roadway and the construction roadway structure are analyzed when the excavation footage is 2.5 m,3.0 m and 3.5 m.It is considered that the vibration of the arch bottom and vault position of the main cavern structure and the side wall position of the existing cavern structure are greatly affected by the vibration under the blasting action.The stress concentration occurs in the side wall and arch foot position of the main cavern,and the tensile stress is large.When the excavation footage is 3.0 m,the construction safety and construction efficiency can be guaranteed.The improvement effect of shotcrete support with different thickness on blasting vibration is verified by numerical simulation.The vibration velocity of cavern structure and the maximum tensile stress of shotcrete are taken as the main analysis indexes.The simulation results show that shotcrete support can better reinforce the surrounding rock of tunnel.For this project,the concrete spray layer with a thickness of 90 mm can effectively reinforce the surrounding rock,reduce the vibration response of the blasting load,and protect the cavern structure.