Dynamic Loading Effect Analysis Of The Storage Caverns In Bedded Salt Rock Formation After Rheological Damage

Underground salt caverns are considered as the ideal facilities for energy storage and radioactive wastes disposal owing to its properties of favorable creep behavior,very low permeability and damage self-recovery.The single layer of salt rock in our country is thin including several weak interlyers at most situation.According to the aboving characteristics,the existing research on static characteristic of salt rock has been made some progress,like creep and seepage.In this paper,the dynamic stability of cavern in bedded salt rock under seismic action and gas explosion is studied with numerical simulation based on the existing achievements about dynamic property of salt rock.The main research work as follows:(1)The seismic response of salt cavern of single-cell with PWIPP constitutive model and proper seismic wave are analysed considering the effect of internal pressure and embedded depth.The results show that salt caverns at great depth have well seismic resistance stability.Dynamic response of twin cavities with different spacing are analysed as well.Interaction between cavities is negligible when the chamber distance is greater than two times of cavern diameter,acoording to the result of plastic zone and differential stress distribution in surrounding rock.(2)Probability of internal explosion in salt cavern with natural gas is debated in this paper.Fitting waves of explosion is analysed and proposed acoording to the theoretical and experimental study of gas explosion in confined spaces.Explosion response of model with single-and multi-cavities are simulated with PWIPP constitutive model.We can find that the dynamic response of cavern under fitting explosion wave is greater than that under simplified wave.Attenuation results of explosion wave in surrounding rock show that influence depeth of blast is shallow.The influence of gas explosion on adjacent cavern is negligible when the chamber distance is greater than two times of cavern diameter.(3)The srain-rate effect of salt rock strength under different loading rates is simulated with model of specimens,based on the available experimental results about strain-rate effect.(4)Dynamic response are analysed with Userc_d constitutive model under seismic and explosion waves about caverns that considering sufficient rheological damage after excavation.The simulation results are similar to the corresponding regular of PWIPP constitutive model.