Investigation on response of pile and Pile group due to excavation induced Movement

Abstract

Piles are slender members which transfer the loads to deeper soil or rock of high bearing capacity bypassing the soil of lower bearing capacity at shallow depth. They are generally preferred when heavy structural loads have to be transferred through weak subsoil to firm strata. Piles are also used to support structures such as transmission towers, offshore platforms and basement mats subjected to uplifting forces. These piles are also subjected to lateral loads of significant magnitude. One such situation is induced lateral force on piles due to ground movement. Ground movements may occur because of movements due to ground instability and also due to a changing stress-state like deep excavation, tunneling and embankments leading to volume changes within the soil. Changes in the stress state in the ground due to deep excavation cause deformations of the surrounding soil layers and displacements of the foundations of existing structures. This situation may be isky, especially for tall buildings and historical structures. The accurate estimation of these displacements, as well as a safe design of the foundation, becomes a vital task for geotechnical engineers. Due to increase in construction of underground facilities and structures requiring many basement levels; the excavation of ground below several meters becomes necessary. Limiting the damages to neighbouring acilities adjacent to an excavation is a major design consideration when developing amenities in congested urban areas. The ground movement happening over a region by excavation is also a prime concern for geotechnical engineers. Additional forces on foundations due to ground movements are high particularly for foundations like piles and designing them for such situations becomes necessary particularly in the present scenario of deep excavations and underground constructions in urban areas. newline