Papers by Keyword: Consolidation

Abstract: Clay soil is one of the problematic soils due to its natural states which have low bearing capacity and high compressibility. The effect and problem of the clay soil characteristic creates a problem for construction especially excessive settlement and this can lead to unstable and potential cracks of engineering structures. At presents, there are few of soil improvement types can be carried out to overcome these problems, and electro osmotic consolidation is one of the options. This method has been applied many years ago especially in european countries. The study encompasses the determination of water content, atterberg’s limits and undrained shear strength after electro osmotic consolidation treatment of clay soils taken from 0.5 m and 1.5 m at southwest part of johor. All the samples were tested according to BS1377:1990. An experimental study was implemented in a pvc cylinder tube having dimensions of 300 mm height and 100 mm diameter. In the results of electro osmotic consolidation tests by installing copper spring electrodes, the measured undrained shear strength was increased considerably at the anodes especially compared to the initial undrained shear strength due to electro osmosis process and consolidation. As laboratory studies of its measurement have shown, the application of electro osmotic consolidation after the application of a direct current applied voltage of 10 volts, at the anodes especially: (i) a decrease by approximately 35% in water content; (ii) an increase around 29% in undrained shear strength; and (iii) a decrease about 21% in index plasticity. The results obtained in this study shows that the electro osmotic enhanced 15 kpa vertical loading consolidation is a feasible approach in strengthening of south west soft clay in johor. It can be clearly suggested that the higher the voltage applied in the system, the higher readings of undrained shear strength and the lower of water content especially at the anodes.

Abstract: One-dimensional consolidation equation of unsaturated soils was derived in order to solve this special case of consolidation. The presented equation, not similar to Terzaghi’s equation, is a type of absolute nonlinear partial differential equation, and it was solved by finite difference method. An example was analyzed and the case of incompressible fluid consolidation was compared. Finally the experimental results from laboratory tests reported in the literature, was fitted by the presented equation, and the agreement was good. The results show that (1) the process of pore-air pressure dissipation is similar to that of pore-water pressure of saturated soils; (2) the compressibility of pore fluid is not an advantageous factor to quicken the consolidation; (3) the presented equation is effective to analyze the process of consolidation of unsaturated soils which consolidate mainly due to the dissipation of pore-air pressure.

Abstract: In this work, one-dimensional problem has a well-known linear solution and, thus, provides a simple verification of the consolidation capability using numerical solution. The coupling is approximated by the effective stress principle, which treats the saturated soil as a continuum, assuming that the total stress at each point is the sum of an effective stress carried by the soil skeleton and a pore pressure in the fluid permeating the soil. This fluid pore pressure can change with, and the gradient of the pressure through the soil that is not balanced by the weight of fluid between the points in question will cause the fluid to flow: the flow velocity is proportional to the pressure gradient in the fluid according to Darcy's law. A typical case is a consolidation problem. Here the addition of a load to a body of soil causes pore pressure to raise initially; then, as the soil skeleton takes up the extra stress, the pore pressures decay as the soil consolidates. The Terzaghi problem is the simplest example of such a process. For illustration purposes, the problem is treated with and without finite-strain effects. The numerical solution agrees reasonably well with the analytical solution, with some loss of accuracy at later times.

Abstract: Among the available methods of disposing sludge from water treatment is to dispose them in landfills or to deposit them at a certain location to form lagoons. Once fully deposited, the landfills or lagoons can be converted into a recreational area or even housing area depending upon the final strength of the sludge. An attempt to look into the possibility to stabilize and strengthen sludge from underground water source using electroosmotic method was carried out in a laboratory environment. Several samples of sludge containing predominantly ferrous oxide were placed in specially fabricated electro-osmotic cells. Direct current was then applied through the samples via copper electrodes at the two ends of the samples. All the samples were subjected to seven days of treatment with variation in the surcharge/load imposed and voltage applied on the samples. Results from the tests demonstrated positive effects on the treated sludge samples. There were significant increase in the shear strength and reduction of moisture content which could be an early indication that sludge which predominantly contains ferric oxide could be strengthen by means of electroosmotic stabilization.

Abstract: Using the mixed powders containing gas-atomized powders of metallic glassy alloys (Cu₅₀Zr₄₅Al₅, Fe₇₃Si₇B₁₇Nb₃, Ni_52.5Nb₁₀Zr₁₅Ti₁₅Pt_7.5) blended with high-conductive Cu particulates, we produced bulk metallic glassy alloy composites with high strength and high electrical conductivity, as well as with enhanced plasticity and satisfying large size requirements by a spark plasma sintering process. In this paper we present and review our research results on the fabrication and properties of the bulk glassy alloy composites by the spark plasma sintering process.

Abstract: Due to the characteristics of the physical mechanical properties of soft ground, reasonable foundation treatments are usually necessary before it meets the need of foundation deformation and load requirements. How to choose a reasonable foundation treatment method which has obvious virtues of economical expenditure and shorter construction period is an urgent problem emerging in engineering construction in the Pearl River Delta. While drainage sand well is used widely in soft soil foundation treatment in the Pearl River Delta. In this paper, a simplified calculation method is proposed to calculate the strength of soft soil foundation treated by sand well after drainage consolidation.

Abstract: The monitoring mechanisms of open-source IaaS software OpenNebula and monitoring system Ganglia were analysed. Reduce overload of retrieving resource usage information by deploying the Ganglia monitoring agent. And for improving the robustness of monitoring subsystem, we take measures on the privileged domain of virtualization nodes to hide the agent to prevent regular or malicious users checking, modifying, unloading or killing it. The mechanism is very helpful to enhance the effectiveness, reliability and sturdiness of the monitoring system of IaaS platforms.

Abstract: The squeezed branch pile is a kind of frictional end bearing pile which is variable cross-section, a new type of pile foundation with characteristics of high bearing capacity and low settlement. In order to explore vertical settlement regularity of the squeezed branch pile, this paper carries out the theoretical analysis and experimental research on the consolidation settlement law of the squeezed branch pile through the numerical method and static load test. The results of numerical analysis and experimental research show that vertical consolidation settlement is reduced along with increase of the squeezed branch pile diameter, and the settlement of the squeezed branch pile is given priority to consolidation.

Abstract: In this paper, alanine which was homologous with wool fibers and the crosslinker glutaraldehyde were used to consolidate fragile wool fabrics. As a bifunctional crosslinker, glutaraldehyde can react with amine groups both in wool and alanine. With glutaraldehyde crosslinking at different concentrations, the breaking strength, molecular structure and surface morphology of the wool were investigated. As a consequence, the consolidation with alanine and glutaraldehyde led to a positive effect on the mechanical properties of fragile wool fabrics, resulting in increased breaking strength. However, the results of SEM and FTIR showed that the consolidation had no obvious influence on the morphology and chemical structure of fragile wool fabrics.

Abstract: Based on the solution of one-dimensional consolidation model of T-shaped bidirectional soil-cement deep mixing column composite foundation and its calculating program deduced by the separation of variables and Laplace method. This paper discussed the consolidation and settlement characteristics of composite foundation under the conditions of different loading modes, foundation reinforcement modes, diameter of enlarged pile head and pile spacing. The results indicate, the soil layer in the region of enlarged pile head hardly be influenced by above factors, the lower soil layer and soft substratum soil are influenced greatly. Loading mode has a large effect on the consolidation, when loading instantaneously, the rate of consolidation is faster than that of loading constantly. The consolidation and settlement behavior of composite foundation reinforced by T-shaped bidirectional soil-cement deep mixing column and traditional bidirectional deep mixing column is much better than the original natural foundation. When the other parameters stay the same, consolidation degree and total settlement decrease with the increase of enlarged pile head diameter. With the increase of pile spacing, consolidation rate of the composite foundation decreases significantly, but the settlement value increases rapidly on the contrary.