← Back to Sessions

SPE Rock-valley-direct-comparison Chemical Explosions Near-field 3D Ground Motion Simulations and Predictions

Description: 

Rock Valley Direct Comparison (RV/DC) is Phase III of the Source Physics Experiment (SPE). RV/DC includes two chemical explosion experiments. The first, RVDC-1, is a 1-ton equivalent TNT located at 1.8km depth, while the second, RVDC-2, is a 10-ton equivalent TNT located at 1.7km depth. The local geology of the site is complex and encompasses a deep hard-rock, dolomite starting at 1km depth, and the shallow 1km is a mixture of tuff and sedimentary layers, deposited under a rugged topography. The water table is located 500m deep. The layered beds are crosscut by a series of faults. The source package is sized to be 3.5 to 4.5 feet diameter emplaced in a 4 to 5 feet diameter ground-zero (GZ) borehole. The characterization of the geology is limited and includes one straight continuous core-hole (CH), and two directional observation boreholes (OB) cored as needed sporadically. Based on this complex geological conceptual setting, we have conducted 3-dimensional non-linear numerical simulations of the ground motions generated from both explosions. First, we used deterministic geophysical properties of the layered model and assessed the response of the system with and without the faults to assess their effect on the anisotropic radiation of the ground motions. Second, we have included stochastic variations in the geological layers. We adopted a scheme of including stochastic discrete fractures in the deep dolomite layer, while a continuous stochastic variation of lenses in the shallow geological layers. Assessing the effect of those stochastic parametrizations on the overall response of the system were obtained using a sophisticated interval Monte Carlo method. Material models have been calibrated to laboratory experiments and assessed under variably saturation conditions. Differentials of ground motion under different conditions of physical and structural uncertainties are then derived for both RVDC-1, RVDC-2, and a hypothetical earthquake.

This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Session: Accuracy and Variability of Physics-based Ground Motion Modeling - I

Type: Oral

Date: 4/15/2025

Presentation Time: 02:45 PM (local time)

Presenting Author: Souheil

Student Presenter: No

Invited Presentation: 

Poster Number:

Authors