The failure anisotropy of geomaterial is inherently related to the microstructure such as grain arrangement, bedding, and crack pattern. This paper presents a formulation of an anisotropic failure criterion in three-dimensional (3D) stress space on the basis of the combination of the SMP criterion and a material microstructure tensor proposed in previous publications. The criterion is specialized for cross-anisotropic granular-material based on the loading direction and the direction of material bedding determined by two angles in 3D stress space. Consequently, it can describe the variation of strength resulting from the changing of the direction of material bedding and the changing of the stress state. Furthermore, the proposed criterion can capture the cross-anisotropic strength behavior of granular materials, which is concluded from the comparisons between its predicted and relevant experimental results.

This paper presents the findings from both the detailed site investigations and the computational analyses on the Zipingpu concrete-faced rockfill dam (CFRD), a 156-m high dam in which 100-cm permanent settlement and 60-cm horizontal displacement occurred during the 2008 Wenchuan, China, earthquake. The Zipingpu CFRD was 17 km away from the epicenter and was considerably damaged by the Wenchuan earthquake. It was estimated that the peak acceleration in the top of the dam along the axial and vertical direction was about 20.0 m/s2, and the peak acceleration at the river level was about 16.0 m/s2. It was calculated that peak acceleration of dam bedrock was more than 5.0 m/s2, and the intensity (Chinese scale) was more than IX. Based on an in-situ investigation, the peak value of settlement of the dam crest reached 744.3 mm, and the peak value of horizontal displacement toward the right and left abutment are 226.1 mm and 106.8 mm, respectively. The actual experience of the peak acceleration and sei...

Blast-induced craters and ground vibrations caused by underground explosions are the foundation of explosion-resistance design for underground structures and protective facilities. In this study, large-scale blast experiments were performed in the field to investigate the characteristics of the ground vibrations and craters induced by single underground explosions in a loose, wet sand medium. Results from eight single blasts with emulsion explosives ranging from 200 to 400 g and buried depths ranging from 0.5 to 1.0 m are presented in this paper. A numerical simulation for Blast E8 using the coupled smoothed-particle hydrodynamics and finite-element method (SPH-FEM) is also presented. The influences of charge weight and buried depth on blast-induced crater formation and ejecta shape were studied. The experimental data for crater diameter were found to be roughly identical to the results suggested for wet sand. An empirical fitting formula for the ground vibration induced by single underground explosion in a loose, wet sand medium was developed using the vertical and radial components of peak particle velocity (PPV) obtained from the experiments. A numerical simulation using a coupled SPH-FEM was modeled to validate the experimental results and prove the method’s ability to model the blast-induced crater and ground vibration.

In order to study the effect of particle size distribution on the critical state of rockfill, a series of large‐scale triaxial tests on rockfill with different maximum particle sizes were performed. It was observed that the intercept and gradient of the critical state line in the e − p^′ plane decreased as the grading broadened with the increase in particle size while the gradient of the critical state line in the p^′ − q plane increased as the particle size increased. A power law function is found to appropriately describe the relationship between the critical state parameters and maximum particle size of rockfill.

Particle breakage was reported to have great influence on the mechanical property of granular materials. However, limited studies were conducted to quantify the detailed effects of relative density and initial grading on the particle breakage behaviour of granular materials under different confining pressures. In this study, a series of monotonic drained triaxial tests were performed on isotropically consolidated granular materials with four different initial gradings and relative densities. It is observed that particle breakage increases as the confining pressure or relative density increases, whereas it decreases with the increasing coefficient of uniformity. Due to particle breakage, the grading curves of granular materials after triaxial tests can be simulated by a power-law function with fractal dimension. As the confining pressure increases, the fractal dimension approaches the limit of granular materials, i.e., 2.6. A unique normalized relation between the particle breakage extent and confining pressure by considering relative density and grading index was found.