Prediction of Ground Vibrations During Pile Driving

            
             Pile foundation is widely used whether if the bearing capacity of soil layer under the building could not support the building and the force itself (Sardjono HS, 1988), or if the bearing capacity of the soil could support the structure of the building and the force on the depth from the soil surface > 8 m (Bowles, 1991). .
             However, pile driving inevitably causes varying degrees of ground vibrations, which both may damage the surrounding structures and environment comfortable. .
             Regarding to that reason, this study analyze the ground vibration during pile driving using finite element method. The result is peak particle velocity (ppv) as the parameter that used to analyse ground vibration. It shows the level of vibrations from several points and used to determined allowable ppv as a priliminary based before the constructions, hence it will help geotechnical engineers in designing and executing driven pile installation so as unjust restrictions can be avoid.
             2 2-D FEM MODELLING.
             The model of finite element method is built using Software Package, PLAXIS. Mohr Coloumb was used for clay, Hardening soil was used for sand and Linier Elastic modell for pile with axisymmetric analysis. The load was added on the middle of surface at the top of the pile with a certain value of frequencies. Considering the dynamic loads, Standard fixities were considered and standard absorbent boundaries were used at the both side and bottom of pile to avoid spurious reflections. .
             Both the soil and pile were modelled with 15-noded elements. Interface elements were placed around the pile to model the interaction. While, the boundaries of geometry was used the distance of 340 meter and the depth was 40 meter to obtain the maximum range of vibration, where the ppv that indicated from the modell shows the the vibrations would not affected to the damage of building structure. .
             2.1 Material Modell.
             The parameter that used for this modell are obtained from the correlation of N-SPT value as an input parameter of ground vibrations modell using finite element method.