Laboratory Shake Table Study on the Liquefaction Characteristics of Poorly Graded Sands

Soil liquefaction is a critical geotechnical phenomenon that typically occurs during earthquakes, especially in saturated, poorly graded sands. These sands consist of particles of similar size and lack cohesion, making them highly susceptible to seismic shaking. When an earthquake strikes, the pore water pressure within the saturated sand increases, reducing effective stress and causing the sand to behave like a liquid. This transformation can lead to severe ground deformation, structural damage, and surface manifestations. This project focuses on investigating the properties and behaviour of different types of poorly graded sands under simulated earthquake conditions using a shake table in a laboratory setting. Soil samples are collected from Machilipatnam. These locations are chosen due to their geological vulnerability to liquefaction. Before conducting shake table tests, various geotechnical tests are performed. Once the baseline properties are recorded, the samples are subjected to controlled shaking on the shake table to simulate different earthquake magnitudes. The objective is to analyses how poorly graded sands respond to varying seismic intensities, identify the minimum magnitude required to trigger liquefaction, and observe changes in sand behaviour during and after liquefaction. Post-test evaluations will focus on changes in strength, density, and structural integrity. Additionally, the variation in soil properties after liquefaction—such as changes in permeability, compaction, and shear strength—will be thoroughly tested to understand the long-term impact on ground stability.