Ground Engineering with Granular Inclusions for Loose Saturated Sands Subjected to Seismic Loadings

摘要

Sites having predominant loose sand deposits are prone to many hazards, especially under seismic loading conditions. Among different forms of seismic risks, liquefaction is being considered as a crucial hazard when the deposit is saturated/with high ground water level. Ground improvement methods are commonly employed to improve the natural site conditions under such situations for better performance of various engineering structures. Ground treatment by granular inclusions in columnar form can offer effective solution than most other ground improvement methods. This paper presents the review of various aspects of ground engineering of loose saturated sands with granular piles/stone columns. A short discussion on the seismic hazards associated with loose sand deposits with main focus on liquefaction followed by the outlines of the recent developments on the application of granular inclusions in the form of stone columns/granular piles as general ground improvement method as well as seismic hazard mitigation measure are presented. New design charts are developed based on pore pressure generation and dissipation considering various installation and behavioral effects and are discussed and compared with the original design curves. It is concluded that the granular inclusions are very effective in resisting the effects of seismic loading on loose saturated sands. It is also recommended to consider various affects of the granular inclusions together while designing the ground engineering system.