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Although permanent ground movement can cause devasting damages to the infrastructures, contributions assessing the effect of faulting on earth dams are limited with no notable experimental outcomes. This paper aims to provide conceptual information by investigating the response of earth dams with a clayey core subjected to reverse fault rupture using centrifuge experiments. The influence of the earth dam's location on the fault tip and the effect of alluvial foundation thickness beneath the dam was addressed by eight centrifuge tests at 60-g centrifugal acceleration. One model also explored the fault rupture-earth dam interaction considering a soil-cement cut-off wall beneath the center of the core. Distortion, sliding, and rotation of cores were observed as consequences of reverse faulting depending on the point of intersection between the dam body and fault trace. An increase in the core deformation was also captured for dams on thinner foundation layers. The freeboard height of the dam also decreases by 48%–90% of the vertical fault throw and should be considered in the design phase to avoid overtopping. • Centrifuge tests are conducted for evaluating fault rupturing through the earth dams. • Effects of fault location and alluvial foundation layer on the response of dams were investigated. • No transverse cracks were observed in cores due to the faulting. • Bending, sliding, and vertical movement of cores were captured in different vertical fault throws. • The freeboard height of the dam also decreases by 48%–90% of the vertical fault throw. [ABSTRACT FROM AUTHOR]

Considering the devastating damages of 'forward-directivity' on structures, a series of finite element models were conducted to evaluate the seismic performance of cantilever retaining walls under near-fault excitations. The wavelet approach was used to extract the velocity pulse of near-source motions, and a semi-artificial records reagent far-field earthquake was produced. Both were then imposed on the model, separately. The results indicated a vivid difference in lateral displacement, in which some cases up to differences of experienced 85% and forces along the walls were approximately equal. In view of this finding, a wide range of PGAs was applied to the near-fault scenarios of the models. The captured movements were compared with the recommended criteria for performance-based aseismic design of retaining structures. According to the numerical analysis, in most earthquakes, for accelerations exceeding 0.4 g, lateral displacement of the wall had a higher value than the permissible proposed limits. Also, accelerations exceeding 0.6 g for both near and far-field records resulted in wall failure (>5% H). The final section of this research presents a comprehensive parametric study on the effects of ground motion characteristics and soil mechanical properties on system performance. [ABSTRACT FROM AUTHOR]

This paper presents the results of two physical test series, including shaking table and centrifuge modeling, on two super-structures with different frequencies and supported by piled raft foundations in a dry sand bed. While the height and weight of two super-structures were kept constant, the axial force and bending moment of piles, as well as horizontal displacement of super-structures were recorded during seismic loadings. The input seismic loadings were given different amplitudes and frequencies. The shaking table and the centrifuge test results indicated that the super-structure frequency strongly affected the pile-raft system responses. Based on the centrifuge test results, the super-structure had larger horizontal displacement, when the excitation frequency was close to system frequency with low base acceleration (0.14 g), while subsequently, axial force and bending moment of piles increased. In high input base acceleration (0.4 g), excitation frequency dominated the super-structure response, and larger responses occurred at smaller (1 Hz) input excitation frequency. [ABSTRACT FROM AUTHOR]

Different case studies have demonstrated that lateral spreading induced by liquefaction was one of the main causes of severe damage to a significant number of fundamental structures supported on pile foundations in the aftermath of many major earthquakes. Consequently, a series of shaking table tests were performed in this study to evaluate the different responses of a single pile and a group of 2*2 circular piles subjected to liquefaction-induced lateral spreading in sandy soil with an infinite inclined slope, as well as compare the response of this pile group in the presence of three different types of protection piles. Protection piles included circular piles upstream, finned piles downstream, and circular piles upstream. The instrumentation results indicate that using finned protection piles with the same cross-sectional area as circular piles demonstrated superior performance in disturbing the soil flow and significantly reduced (about 24–50%) the lateral force exerted on the main piles. The dependence of pile response on the location of protection piles relative to group piles was also investigated through a comprehensive comparison. • Finned piles are investigated in the action of the lateral spreading using a shaking table. • Performance of finned and circular piles to protect a 2*2 pile group is determined. • Finned piles reduce the bending moments of main piles more than circular piles. • Soil pressures exerted on protected piles are compared with JRA and JSWA guidelines. • Finned piles have a better performance in disrupting the soil flow. [ABSTRACT FROM AUTHOR]

Abstract: Accurately predicting pile shaft resistance when designing pile foundations is necessary for ensuring appropriate structural and serviceability performance. The scope of this research includes four main components: (I) compiling shaft resistance datasets obtained from the published literature; (II) developing two artificial neural network (ANN) and non-linear multi regression models for predicting pile shaft resistance using cone penetration test (CPT) results; (III) investigating the influence of input parameters on the resulting shaft friction and their degrees of importance; and (IV) assessing the relative accuracies of the presented models using a number of traditional methods. It is quantitatively demonstrated that the ANN and non-linear multiple regression models proposed in the current study out perform the traditional methods and can be used by engineers to accurately predict pile shaft resistance. [Copyright &y& Elsevier]