The computer program CA2 (Continuum Analysis, 2-dimensional), which can solve two-dimensional large strain plasticity problems, is used to model PILE DRIVING. The strength of the soil is characterized by a Mohr-Coulomb elastic-perfectly plastic model, and a distinct element approach is used to model PILE-hammer interaction. Several numerical tests are performed to demonstrate the importance of different parameters involved in PILE DRIVING.

Impact PILE DRIVING is a multi-component problem which is associated to multi-directional ground vibrations. At first, vibration is transferred from the hammer to the PILE and then to the common interface of PILE and soil. This is then transferred to the environment and has great impact on the adjacent structures, causing disturbance to residents and also damage to the buildings. It is of high importance to have sufficient estimation of PILE DRIVING vibration level in order to maintain the comfort of residents near the site and also to prevent the structural damage to buildings. In this study, a finite element model, using ABAQUS, with the ability of simulating continuous PILE DRIVING process from the ground surface, was introduced. The model was verified by comparing the computed peak particle velocities with those measured in the field. Parameters affecting the peak particle velocity (PPV), for example elastic modulus, shear strength parameters, impact force, PILE diameter, etc. were considered, and variations of PPV was investigated. Results of present study indicated that PPV at the ground surface does not occur when the PILE toe is located on the ground surface; as the PILE penetrates into the ground, PPV reaches a maximum value at a critical depth of penetration. Moreover, the amplitude of vibration on the ground surface reduced logarithmically with increasing distance to the PILE. Also, on the ground surface and radial distances of 3 to 20 m, maximum particle velocity occurred between 1 to 5 m depths of PILE penetration. The results showed PPV as being directly proportional to the hammer impact force, PILE diameter, friction angle and cohesion intercept and inversely proportional to the elastic modulus of the soil.

A finite-difference based continuum numerical model is developed for the PILE-soil dynamic response during PILE DRIVING. The model is capable of simulating the wave propagation analysis along the PILE shaft and through the soil media. The PILE-soil media, loading and boundary conditions are such that axisymmetric assumption seems to be an optimized choice to substantially reduce the analysis time and effort. The hydrostatic effect of water is also considered on the effective stresses throughout the soil media and at the PILEsoil interface. The developed model is used for signal matching analysis of a well-documented driven PILE. The results showed very good agreement with field measurements. It is found that the effect of radiation damping significantly changes the PILE-soil stiffness due to the hammer blow. The PILE tip response shows substantial increase in soil stiffness below and around the PILE tip due to DRIVING efforts.

PILE-DRIVING is a common method of foundation construction where the soil is not strong enough to support the load of the structure through conventional shallow footing. This method is widely used in residential and industrial building, bridges, highways and etc. Along with the benefits of using this method, PILE DRIVING is also a source of negative environmental effects. Noise and air pollution are the most commonly expressed concerns, but, ground vibrations originating from the PILE DRIVING impact also have important adverse effects. They can cause disturbances to adjacent structures and also disrupt the operation of nearby sensitive equipment and facilities. Permanent settlement, densification and liquefaction may also occur in the soil due to such vibrations.A common factor for evaluating the amount of vibrations is peak particle velocity (PPV), which is maximum velocity that soil particles reach during the PILE DRIVING process. PPV is the maximum velocity that a soil particle experiences during the DRIVING of a PILE from the ground surface to the desired depth. Ground motion due to PILE DRIVING generally depends on (1) the source parameters (method of DRIVING, energy released, and PILE depth), (2) the interaction between the DRIVING machine, the PILE and the soil, and (3) the propagation of waves through the soil.In this article, a two-dimensional finite element model is validated using a case study of PILE-DRIVING data conducted in the Chennai site in India. Then, by modeling a PILE in sandy soil with different soil relative densities, Poisson ratio, moduli of elasticity, Unit weight, friction angle and damping ratio, the effects of these parameters on vibrations of the ground surface, and peak particle velocity on the surface, were studied. The results showed that the increase in friction angle and Poisson ratio in-creases the PPV. However, increase in the modulus of elasticity, damping ratio and soil unit weight, decreases the PPV. Also, scrutiny of PPV occurrence time shows that by variation of the in uencing parameters, except the modulus of elasticity, this time is almost constant.

PILE DRIVING is one of the PILE construction methods to install prefabricated concrete PILEs using special tools. DRIVING method and its process is one of the most important aspects of implementation of this PILE, so that the lack of sufficient accuracy to this problem, in addition to reducing operation efficiency, affects the surrounding environment and soil. In this paper, the behavior of cylindrical and tapered hollow PILEs were investigated with real tests and numerical analyses using FLAC3D software. The efficacy of PILE geometry such as cylindrical and tapered hollow PILEs is analyzed in PILE DRIVING under hammer impact...