Affiliations: Department of Civil Engineering, Indian Institute of
Technology Madras, Chennai, India | Department of Civil Engineering, Indian Institute of
Technology Guwahati, Guwahati, India
Abstract: Pile foundations are frequently used in very loose and weak
deposits, in particular soft marine clays deposits to support various
industrial structures, power plants, petrochemical complexes, compressor
stations and residential multi-storeyed buildings. Under these circumstances,
piles are predominantly subjected to horizontal dynamic loads and the pile
response to horizontal vibration is very critical due to its low stiffness.
Though many analytical methods have been developed to estimate the horizontal
vibration response, but they are not well validated with the experimental
studies. This paper presents the results of horizontal vibration tests carried
out on model aluminium single piles embedded in a simulated Elastic Half Space
filled with clay. The influence of various soil and pile parameters such as
pile length, modulus of clay, magnitude of dynamic load and frequency of
excitation on the horizontal vibration response of single piles was examined.
Measurement of various response quantities, such as the load transferred to the
pile, pile head displacement and the strain variation along the pile length
were done using a Data Acquisition System. It is found that the pile length,
modulus of clay and dynamic load, significantly influences the natural
frequency and peak amplitude of the soil-pile system. The maximum bending
moment occurs at the fundamental frequency of the soil-pile system. The maximum
bending moment of long piles is about 2 to 4 times higher than that of short
piles and it increases drastically with the increase in the shear modulus of
clay for both short and long piles. The active or effective pile length is
found to be increasing under dynamic load and empirical equations are proposed
to estimate the active pile length under dynamic loads.
