Abstract: The influence of blasting construction of new tunnel on the side wall a large-section underground cavern on the stability of adjacent underground caverns is the purpose of this research.Based on the water diversion project from Ningbo to Hangzhou bay,blasting vibration data monitored in a section of Tingxia tunnel from the blasting excavation of the Xixia tunnel are used to obtain vibration velocity distribution law.Finite element model established by LS-DYNA is used to simulate burn cut blasting process and obtain the distributions of vibration velocities and stresses in adjacent caverns under blasting effect.The stability of underground caverns are then assessed by considering the effect of dynamic loads.The calculation results show that the blasting vibrations predicted by numerical simulation agree well with the data of field tests.The vibration velocity and tensile stress reach the maximum values at the near-field area on the side wall closer to the blast source,which leads to a higher possibility of tensile failure.The distribution law of vibration velocity is similar to that of maximum principal stress.Combining with the criterion of rock tensile strength,the data of maximum principal stress and vibration velocity were fitted,and the safety criterion of peak vibration velocity was proposed.When the vibration velocity exceeds the critical value of 45.82cm/s,measures should be taken in time and protection should be strengthened.This research work can provide reference for similar tunnel blasting construction and vibration control.