Non-Linear Seismoacoustic Responses of Explosions in Different Rock Types and Water: Comparisons With Experimental Data
Description:
We have performed quasi-3D high-resolution numerical simulations of surface and underground explosions using LLNL’s massively parallel hydrocode GEODYN to assess the impact of parameters such as yield, height of burst (HOB), depth of burst (DOB) and geological material on the resulting overpressure in air and seismic motions at distance. The material properties span a large spectrum from hard rock, such as granite with low porosity, limestone, sandstone, tuff, salt, and very weak material, such as dry and wet alluvium. Arrival times to surface station are determined by the shock wave propagation and the coupling of ground motion. We show that overpressures and peak velocities due to the same yield at the same scaled HOB/DOB are functionally very similar regardless the geological fabric and therefore the response can be scaled. Moreover, the impulse is calculated by integrating the initial positive pressure time-history. It was found that the functional form of the impulse as a function of scaled HOB/DOB is also consistent for emplacements above ground, at ground level and down to depths where cratering occurs regardless for all geological materials even though the material properties show drastic geomechanical variations. While the current study used numerical simulation from idealized blast and settings, additional factors can complicate observed seismic signals and bias the amplitudes and subsequent yield and HOB/DOB estimates. For example, we show that the emplacement lithology strongly impacts seismic amplitudes for deeply buried explosions. Furthermore, the behavior with HOB/DOB is different for the materials considered. Results are compared with legacy chemical and nuclear experimental data, and the more recent forensic (LSECE) and proof-of-concept (MDE) surface explosions conducted at the Nevada National Security Site.
Session: Advances in Marine Seismoacoustics
Type: Oral
Date: 4/18/2023
Presentation Time: 02:30 PM (local time)
Presenting Author: Souheil M. Ezzedine
Student Presenter: No
Invited Presentation:
Authors
Souheil Ezzedine Presenting Author Corresponding Author ezzedine1@llnl.gov Lawrence Livermore National Laboratory |
Avrey Cashion atcashi@sandia.gov Sandia National Laboratories |
Kenneth Laintz laintz@lanl.gov Los Alamos National Laboratory |
Oleg Vorobiev vorobiev1@llnl.gov Lawrence Livermore National Laboratory |
William Walter walter5@llnl.gov Lawrence Livermore National Laboratory |
|
|
|
|
Non-Linear Seismoacoustic Responses of Explosions in Different Rock Types and Water: Comparisons With Experimental Data
Category
Advances in Marine Seismoacoustics