A high strain‐rate constitutive model for sand and its application in finite‐element analysis of tunnels subjected to blast

Abstract

SUMMARY The paper presents a constitutive model for simulating the high strain‐rate behavior of sands. Based on the concepts of critical‐state soil mechanics, the bounding surface plasticity theory and the overstress theory of viscoplasticity, the constitutive model simulates the high strain‐rate behavior of sands under uniaxial, triaxial and multi‐axial loading conditions. The model parameters are determined for Ottawa and Fontainebleau sands, and the performance of the model under extreme transient loading conditions is demonstrated through simulations of split Hopkinson pressure bar tests up to a strain rate of 2000/s. The constitutive model is implemented in a finite‐element analysis software Abaqus to analyze underground tunnels in sandy soil subjected to internal blast loads. Parametric studies are conducted to examine the effect of relative density and type of sand and of the depth of tunnel on the variation of stresses and deformations in the soil adjacent to the tunnels. Copyright © 2012 John Wiley & Sons, Ltd.

A coupled chemo‐viscoplastic cap model for simulating the behavior of hydrating cemented tailings backfill under blast loading

“…The direction of is given by f and in the outward normal direction of a dynamic yield surface, that is, the associated flow rule is used for the viscous behavior of the material. As can be observed, in the overstress theory of Perzyna for characterizing the viscoplastic behavior of materials, ϕ ( f ) is used to quantify the overstress, that is, the distance between the viscoplastic stress state and the yield surface . Equation (a) is used in the present study, and the parameters η , N , and f 0 can be determined by trial and error .…”

“…Alternatively, to take the effect of high strain rates into account for both strength and stiffness, formulations of viscosity have been integrated with conventional plasticity, that is, resulting in the so-called viscoplasticity. There are two popular viscoplastic models to account for the high strain rate phenomenon in the literature, the viscoplastic formulations of Duvaut-Lions [90][91][92][93] and Perzyna [70,71,[76][77][78][79]94].…”

“…Similar limitations are found in the work of van Gool . Therefore, although a variety of soil models for blasting are available in the literature to date with good outcomes , these models are not applicable to hydrating CPB. A model that is directly applicable to CPB is urgently needed, given the fact that production blast remains the routine in the current operations of mines.…”

Numerical Simulation of a Deep Excavation near a Shield Tunnel

“…Simulation using tetrahedral elements is more accurate and faster than triangular prisms and hexahedra solid elements. [20] Therefore, the tetrahedral elements are adopted in this paper. Block elements, beam elements and contact elements were used to simulate the soils, the inner struts and the interaction between the soil and the piles, respectively.…”

Dynamic Analysis of Twin Tunnel Subjected to Internal Blast Loading

“…Liu [19] performed finite element analysis of underground tunnels with cast-iron lining subjected to blast loading simulated using CONWEP. Higgins et al [14] carried out plain strain analysis of tunnel in sand subjected to internal blast loading considering high strain rate stress-strain response of soil using a bounding surface plasticity constitute model. However, their study assumed elastic stress-strain response for concrete lining in the tunnel.…”