Soil Injection Technology Using an Expandable Polyurethane Resin: A Review

Abstract

The soil injection, using an expandable polyurethane resin, holds a unique potential for settlement compensation, lifting, and strengthening the foundations of existing buildings and structures. Although various research and case studies regarding this technology have been published, these studies emphasized the technology’s effectiveness in the rapid lifting process. Nevertheless, there is no complete understanding of the technology, yet, that gathers necessary data leading to a better recognition for this technology in the theoretical understanding and the practical applications. This article aims to provide a comprehensive understanding of this technology. The injection process, the resin’s mechanism, and actual propagation in the soil’s massive, the modified physic-mechanical properties of the soil, the expansion process, the consumption of the resin, and the durability are extensively reviewed in this article. Besides that, this article aims to demonstrate the advantages and limitations of this technology in practical applications. The review also explores the existing finite element models used to calculate the strength and stiffness parameters, evaluating the bearing capacity of the composite (soil-resin) and the settlement after the injection process.

Characterization of polyurethane foam conditioned sand

“…Soil conditioning is defined as an artificial change in the properties of soil to improve its performance when subject to different loads [1].…”

“…It is suitable for all soil types because it hardens quickly, is easy to inject, is the light weight of the resin, and is not affected by ground water [9]. Polyurethane resin is lightweight material; the stressstrain curve of different polyurethane samples with different densities demonstrate that increasing the density of Polyurethane increases the failure stress and modulus of elasticity while decreasing the yield strain [1,10].…”

“…with a circular plate 300 mm diameter was conducted on each soil before and after polyurethane injection at a loading rate of 50 kpa. The bearing capacity, settlement, and the modulus of deformation are determined from the following formula[48]: ……………………... (1).…”

Vertical Fiberglass Micropiles as Soil-Reinforcing Elements

“…The traditional ground improvement materials have many restrictions, are costly and not feasible, and, in many cases, might lead to electrochemical corrosions, threatening the whole overlaying constructions. Thus, developing practical and effective methods is a current task to provide stable, safe, and economic reconstruction [ 4 ].…”

Rock Reinforcement by Stepwise Injection of Two-Component Silicate Resin

“…The injection sites are selected according to rock type, groundwater level, etc. [ 1 , 2 , 3 , 4 , 5 ]. A thorough mixing of the resin components is crucial.…”