Dynamic Response of Marginal Soil using SPT, DCPT & Cyclic Simple Shear Tests

Abstract

Coarse-grained soils are preferably used in geotechnical infrastructure projects such as retaining walls and highway embankments due to their superior drainage and frictional properties. However, such materials are not always available on or near the construction site. Given the limited availability, high cost, and transportation issues associated with coarsegrained fill, using the locally available marginal soil for the various infrastructure projects becomes essential. Marginal soils are soils with a high percentage of fines that can be cohesive or non-cohesive. The primary concern with marginal soil is its low permeability, which causes excess positive-pore water pressure evolution during load application. As a consequence, the soil loses shear strength over time. Previous researchers have provided some information on the dynamic behaviour of marginal soils in terms of cyclic strength and pore pressure development. However, more research is needed to understand the dynamic response of compacted marginal soils in terms of cyclic resistance ratio (CRR) using field and lab data. Therefore, an attempt has been made in this study to evaluate the cyclic resistance of compacted marginal soil (clayey sand) by performing stress-controlled cyclic simple shear (CSS) tests in the laboratory and Standard Penetration Test (SPT) and Dynamic Cone Penetration Test (DCPT) in the field. The cyclic strength of marginal soil has been determined as Cyclic Resistance Ratio (CRR) by using laboratory (CSS) and field (SPT, DCPT) test data.

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