Soil Solidification Research Articles

Recycled Technology of Urban Road Construction Waste and Miscellaneous Fill Used as Subgrade Fillings

Continuously increasing municipal renovation and roadbed excavation produced a considerable quantity of solid waste each year such us miscellaneous fill mixed with broken pavement fragments and brickbats, which resulted in a series of urban environment and soil resource issues. Comprehensive recycling technology for soil modification to attain the strength requirements of subgrade fillings from the related road construction codes is necessary and even urgent, since the usual soil replacement is not the economic and environment-friendly method. The field investigation and laboratorial tests hereby had been completed to confirm the application potentials of typical soil specimens selected from different locations. The experimental results indicate some of specimens can be reused as subgrade fillings in road construction immediately and others should be treated by soil amelioration. To further certify the practicality of this recycled technology and broaden its range of application, three typical reutilization and treatment techniques, cold recycling, soil solidification and dynamic consolidation are introduced into engineering projects.

Technology reliability of soil solidification at interstation tunnels operation of the Kiev underground

In the article the basic provisions of technology reliability of soils stabilization during exploitation of the Kiev underground railway running tunnels are considered.

Novel Cementious Materials from Industrial Solid Waste for Silt Soil Solidification

Four kinds of industrial solid waste, granulated blast furnace slag (GBFS), electric furnace steel slag (EFSS), semi-dry flue gas desulfurization slag (FGDS) and gypsum were activated by mechanochemistry to prepare a novel kind of cementious material, DA type soil solidification agent (DA agent). Compared to the traditional cementious materials, this paper evaluated DA agent used in silt soil solidification project. Test results showed that DA-4 was prepared with adding the 40% CFBA, 39% GBFS, 11% OPC clinker and 10% gypsum by mill and more superior in material characteristics. It was found that compressive strength of DA-4 paste and mortar specimens at 28-days cured age were 46.0 and 27.3 MPa respectively; 5% of DA-4 was used to stabilize the silt soil in lab and the maximum dry unit weight, optimum moisture content, unconfined compressive strength and CBR value were 1.754 g/cm3, 15.35%, 1.15 MPa and 95.5% respectively. The hardening mechanism of prepared cementious materials is explained by two points: the sulfite or sulfate activation on alkali blast furnace slag; and the hydration product produced from cement clinker hydration process. Besides test programs of the trial pavement section in site showed that stabilized and solidified silt soils by DA-4 can meet the requirement of subgrade of pavement for strength and stiffness.

Study on soil solidification based on microbiological precipitation of CaCO3

The soil solidifying technology started booming from the 1940s and formed an integrated cross-discipline. This paper aimed to study the effect and mechanism of soil solidification by microorganisms. Soil specimens treated by different methods were designed. Then the compressive strengths of these specimens on day 7 were tested and the situ bacteria culturing technique in soil was investigated. Finally the mechanism of soil solidification by microorganisms was explored according to the decomposition rate of substrate, pH value and the SEM and XRD analysis. Experimental results showed that the soil could be solidified by filling enhancement and precipitation of microorganisms. The compressive strength increased with bacteria A but decreased with substrate B, and soil specimen got a higher strength with bacteria situ cultured. The suitable pH value for bacteria A was 8–9, and the delay of lime addition could make substrate decomposition more completely, lower the influence by the existence of substrate, and improve the strength. In XRD and SEM images, precipitation of CaCO3 could be speculated.

Application of a UV-Curing Resin to Hydrodynamic Studies in Porous Media

Laboratory techniques which have been applied to visualization of flow and transport in porous media include light transmission, matched index of refraction methods, NMR techniques, and use of epoxies. Within the present study, a commercially available UV-curing resin is applied to capturing transport behavior in porous media. This technique provides several capabilities including rapid solidification of soil structure/fluid distribution at preselected locations without stopping flow and the ability to cure the structure of fluid interfaces. The resin cures rapidly, exhibits minimal change in volume during curing, and does not show substantial local flow alteration during curing (despite relatively large increases in temperature during the curing process). This resin holds promise to enhance the ability to study flow and transport through porous media, including the study of particle transport, hydrodynamic dispersion, fluid distributions in multiphase flow, and fingering during infiltration.

Solidification around Horizontal Cylinder in Porous Medium Saturated with Aqueous Solution.

In order to clarify phenomena such as the solidification of soil containing seawater in the ground freezing technique, a horizontal copper cylinder was set in a porous medium saturated with an aqueous solution, and the porous medium, whose size was sufficiently large compared with the cylinder, was solidified by cooling the cylinder. Such a solidification process with natural convection caused by the temperature and concentration gradients in the liquid and mushy regions was studied analytically and experimentally. From the comparison of the analytical results with the experimental ones, the present analysis was found to be useful to simulate this solidification process. By the analysis, the characteristic of the solidification process, especially, the influence of grain size of the porous medium on the solidification phenomenon, was clarified.

Summary of the interdepartmental conference on problems of electrokinetic solidification of muddy foundation beds of marine hydraulic engineering structures

The conference, in which information was exchanged on current developments in the theory and practice of electokinetic solidification of weak soils, discussed plans for the development of an efficient method of electrokinetic solidification of weak margine soils. More than 20 papers were presented on various aspects of marine muddy sediments which included factors such as the constant electrical field on clay soil, physiomechanical and chemical properties, the use of autoclave water glass for soil solidification, electrosilicatization for the solidification of loess and quick sand below ground water level, increase of strength, and chemical solidifying additives.

Chemical Soil Solidification and Chemical Sealing of Leaking Concrete

Chemical Soil Solidification and Chemical Sealing of Leaking Concrete