| The stability problem of near chamber's surrounding rock under blasting dynamic is a complex problem, is concerned with many subjects, such as Explosive Mechanics, Rock Mechanics and Damage Mechanics etc. This paper based on the property theoretical analysis for demolition seismic wave, According to far district weak stress site in demolition, and the development condition of slight crack, put forward blasting dynamic loose circle theory. Made blasting vibration observation in Xinji Mine. And with ANSYS/LS-DYAN, carried out implicit type-explicit type finite element analysis for this project. Calculated the tunnel's self-weight stress site and the spread of seismic wave under blasting dynamic effect.Analyzed the spread mechanism of demolition seismic wave analyses in theory, and analyzed the character of it.Analyzed end stress field of far district slight crackle under blasting dynamic. Discussed the stress condition of periphery crack's local tension stress field created by compressing stress in far field. According to the theory of Elastic Mechanics, Rock Mechanics and Damage mechanics, as well as rock broken mechanism under blasting stress wave in far district, derived the surround rock's dynamic loose circle calculation formula single hole blasting nearby, which made foundation for next dynamic loose circle development calculation by porous blasting at the same time.Put forward that traditional "three anchor" support form should consider blasting dynamic influence to keep the stability of loose circle, prevent the damage of tunnel in the course of using. For tunnel. Put forward new thought for tunnel support.Blasting vibration test results showed the that underground tunnel demolition produced composition signal, the main shock frequency is more than usual blasting frequency, which have many frequencies, the first main frequency is around 70-80 HZ. Through regressing analysis, got blasting vertical vibration speed regression formula, and adopt the method of mathematical statistics, got biggest safety projectile filling of safe blasting formula, and verified it.Use the software of ANSYS/LS-DYNA, simulated the stability of surrounding rock under blasting dynamic by nearby tunnel. First using the implicit analysis function of ANSYS simulated the tunnel's stress and displacement by self-weight, analyzedthe reason of floor lift in tunnel. Then, add the displacement result of node of static force on dynamic analysis as initial condition, turned to LS-DYNA take explicit type analysis, simulated the surrounding rock's stability by blasting stress wave, .made us understand the damage of rock blasting, stress spread and the stability of surrounding rock by blasting dynamic nearby. Compared the simulation results and actual measurement, found the simulated blasting waveform is similar with the waveform of actual measurement, the peak value decay law is basically consistent, the decay law of peak effective stress value follow the law of negative power exponent.
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