YIELD AND DEPTH OF BURIAL HYDRODYNAMIC CALCULATIONS IN GRANODIORITE:IMPLICATIONS FOR THE NORTH KOREAN TEST SITE

摘要: This paper reports on continued research toward establishing a consistent modeling framework for calculating nuclear explosions in earth materials. The model must be with observed phenomena the near-field by correctly 1) resulting explosive cavity radius given yield and depth of burial, 2) accounting correct energy deposition partitioning it into internal (heat plastic strain) kinetic (e.g. radiated seismic) energy, 3) predicting free-field displacement/velocities waveforms 4) measured attenuation peak velocity distance. developed last year satisfies all these criteria has been exercised investigation 2009 North Korean test. main findings reported this are: a) extension to analysis scaled burial free surface effects 2D Earth structure, b) improvement computational equation state (EOS) granite/granodiorite some examples models self-consistency. Our study focuses test site May When compared Denny Johnson (1991) Heard Ackerman (1967) scaling models, results presented show clear preference statistical Johnson. In addition, comparative work between Patton (2011) under project provides lower limit A series sensitivity comprising variation key material properties incorporation topography is being produced at time writing will conference. extended provide additional bounds uncertainty estimates. strong motion hydrodynamics code was used investigate dependence dynamics final (Young’s modulus, shear porosity, etc.). obtained taking Piledriver Hardhat events as design references. following features problem were identified when developing model: profiles stations (near field), source alternatives (iron pill, ideal gas, Hydses/SESAME), partition after shot, displacement size function burial. Previous attempts made existing failed comply one or more features. Tillotson type combined strain-dependent strength implemented observe from various depths explosion. set axially symmetric simulations flat surface, i.e., no topography. Given best estimates parameters fact that there evidence spall test, calculations place minimum 5.7 kilotons 375 meters uniform region. Further refinement numbers only possible introducing realistic profile corresponding site.