Enhancing bearing capacity of shallow foundations through cement-stabilised sand layer over weakly bonded residual soil

Abstract

The addition of a soil–cement reinforcement layer is an alternative to improve the bearing capacity of shallow foundations on weak soils. Recent research with small-scale tests highlighted the influence of the soil–cement layer's geometry and tensile strength in bearing capacity prediction of footings resting on treated layers. This work presents the evaluation of field static load tests of circular steel footings resting on soil–cement layers above a weak residual soil. Results showed on the one hand that traditional methods for predicting bearing capacity in homogeneous soils could be applied when the foundation and reinforcement layer are expected to punch together into the weakly bonded residual soil, without the failure of the reinforcement layer until some prescribed load. On the other hand, methods for continuous double-layer systems could be used where the reinforcement layer is expected to fail before reaching the prescribed load. The failure mode could be predicted by calculating the maximum tensile stress at the bottom of the reinforcement layer at the prescribed foundation load. An equation for this purpose was suggested and successfully tested against real-size field test results. Finally, analytical solutions for determining the bearing capacity were effective in foreseeing the field values.

Live-Scale Testing of Granular Materials Stabilized with Alkali-Activated Waste Glass and Carbide Lime

“…During the intensive search for alternative binders to OPC, alkaline-activated cements (AAC) are rapidly gaining ground, as it involves mostly industrial wastes, and the results are competitive with those produced by OPC. Despite being a recent technique, many studies on alkali-activation of wastes have already shown several advantages of these alternative materials, from high compressive strengths, low shrinkage levels, acid and fire resistance and low thermal conductivity [15][16][17][18][19][20][21][22][23].…”

“…Recent studies have explored the pozzolanic properties of waste glass and its application to a new variety of binders, which include the recycling of different types of industrial waste and by-products (i.e., industrial, agricultural and urban), and have gained notability as soil stabilizers in substitute to OPC in soil-cement [8,17,20,[31][32][33][34].…”