Ground Shock Calculation Parameter Study,Report 1. Effect of Various Nonlinear Elastic-Plastic Model Formulations.

摘要

A parametric study was conducted to determine the effect of using various nonlinear elastic-plastic constitutive model formulations to fit a given set of soil property data in calculating high-explosive (HE),airblast-induced, superseismic ground shock. The code used was a modified version of the 2D axisymmetric LAYER code developed by the Paul Weidlinger firm. A constant shear modulus model, a constant Poisson's ratio model,and a hybrid-type model were employed. Two series of calculations were performed. In the first,the effect of an HE-type airblast on a deep highly compressible layer of soil was investigated for the three different models. In the second series, a two-layer soil profile comprising a shallow layer of highly compressible soil over a deep highly incompressible material was used. The study showed that the radial stress-,velocity-,and displacement-time histories at shallow depths were strongly influenced by the type of constitutive model used to represent the soils'mechanical behavior. Relatively large differences in maximum and final radial displacement were observed for the different models. (Author)