Seismic surface wave methods have become widely adopted methods to acquire the shear wave velocity (Vs) profile of soil over the last two decades. However, the results of these methods are highly dependent on the interpretation and judgment of the person. When the dispersion curve obtained by an MASW test is inverted, it provides numerous Vs profiles equivalent to the dispersion curve. This generates indecisiveness about the actual Vs profile of the soil. Hence, a need has arisen to develop some ways to reduce the uncertainties in the MASW test. In this study, numerical simulation of the MASW test was carried out, and its results were processed with and without borehole data to study the reduction in uncertainties due to the borehole data. The results demonstrate that the availability of borehole information drastically reduces the uncertainties in MASW testing, thereby increasing the accuracy and reliability of the surface wave methods.

Piles are generally used to support superstructures such as bridge abutments, high -rise buildings, and transmission towers, which are subjected to heavy axial forces as well as lateral forces. Nowadays, construction of these structures near the natural or man-made slopes has been increased due to the unavailability of flat grounds. To support the heavy loads coming from the superstructure, normal conventional piles (0.3–0.6 m as per IS 2911) may not be sufficient for some situations, especially located near slopes. The mobilization of the ultimate load-carrying capacity of large diameter piles is different from standard conventional piles given in IS 2911. In this study, the behavior of large diameter piles resting on or near the cohesionless soil slopes is studied using a finite element method. The effect of various influencing parameters like slope gradient, the diameter of pile, length to diameter ratio of pile, and location of water table on the axial and lateral load-carrying capacity of the pile have been studied.

Recent advances in the understanding of deep foundation mechanisms suggest that the pile foundations can be used in both level grounds and the sloping grounds to appropriately support the heavy axial and lateral loads coming from the superstructures. The lateral load-carrying capacity of the pile in the sloping ground is different from the level ground due to the presence of slope and pile location (i.e., edge distance). In this study, extensive numerical analyses were performed to understand the behavior of a laterally loaded pile in cohesionless soil slopes by using the three-dimensional finite element method. Effect of various influencing parameters like slope inclination, relative density, angle of internal friction, modulus of elasticity of soil, unit weight of soil, L/D ratio of a pile, and pile diameter on the laterally loaded pile with a change in edge distance was studied. Results from the numerical analyses were compared with the previous experimental studies. An attempt has also been made to find out critical edge distance (i.e., where the effect of slope angle is negligible on lateral capacity) of the pile for different cohesionless soils with varying slope configurations. The critical edge distance is found to be varying between 5.0–7.5D, 7.5–10.0D, and 10.0–15.0D with slope inclinations of 20°, 30°, and 40°, respectively.

Multichannel Analysis of Surface Waves (MASW) method is extremely popular to carry out seismic site characterization. However, certain uncertainties are existent in this technique. One of the crucial factors which contribute to these uncertainties is the source parameters such as source type, energy and position. This study examined how the change in these parameters influences the uncertainties in the MASW method using numerical simulations. The parameters considered in the numerical simulations are the amplitude of impulse load, duration of impulse load and source offset. For the study, the results of full wave-field simulation were compared with those of plane Rayleigh wave simulation. Results indicate that the change in the amplitude of the impulse load doesn't affect the underestimation of the Rayleigh wave phase velocity. Longer the pulse duration, better the dispersion curve observed at lower frequencies. An increment in the source offset reduces the underestimation

The present paper describes the results of numerical modeling of a dam founded on loose liquefiable deposit using PLAXIS-3D finite element software. Effect of a different dam water level on parameters like displacements, Excess Pore water pressures, Liquefaction potential and Accelerations is studied. El- Centro earthquake motion is applied as input earthquake motion. The results of this study show that different upstream dam water level greatly affects the displacements, excess pore pressure and displacement tendency of the underlying foundation soils and the dam.

During the last few decades various researchers have proposed appropriate experimental and numerical methods to estimate the uplift capacity of granular anchor piles (GAPs) in expansive soils. Surprisingly, very few studies have been performed to determine the uplift capacity of GAPs in loose sands. This paper presents the results of the numerical study to estimate the ultimate uplift capacity of group piles. Numerical analysis is performed using finite element software PLAXIS-3D. The foundation system is assumed to consist of a different number of regularly spaced GAPs installed in loose sandy soils. The analysis examines the influence of factors such as number of piles n and length L to width D ratio, and properties of the granular pile material and compares the efficiency of group of GAP systems of different configurations.

The granular anchor pile (GAP) system is one of the relatively new innovative ground-improvement techniques used to sustain the tensile loads. This paper presents the behavior of a GAP system in a loose sandy soil. The small-scale laboratory tests were conducted on a loose dry sand to investigate the effect of embedded length of pile on the uplift capacity of the GAP system. The results were compared with the numerical analysis using a three-dimesional finite-element analysis software. In the detailed numerical study, the effects of key parameters, such as length (L) and diameter (D) of pile and the elastic modulus of surrounding soil, on the uplift capacity of the GAP were examined. The load-displacement response of the GAP was also analyzed and is reported in this paper. For a constant diameter of the GAP, its ultimate uplift capacity increases as the L/D ratio increases. However, for L/D ratios greater than 10, further increase in the L/D ratio does not contribute to the load sharing significantly. The bulging failure predominantly occurs in the GAP with a higher modulus ratio, whereas the shaft failure occurs with the lower modulus ratios.