The stability of the soil slopes can be judged according to the critical moisture content and the actual moisture content when the soil slopes be in the limit equilibrium state. From the perspective of earth pressure, the critical moisture content is the moisture content when the soil slopes be in the active limit equilibrium state, at this time, the active earth pressure is 0. The critical moisture content can be determined and the stability of the slopes can be judged according to the relationship of the soil parameters and the moisture content and the active earth pressure being 0. The critical moisture content of the upright or declining cohesionless slopes can be determined according to the relationship of the internal friction angle and the moisture content. The critical moisture content of the upright cohesive slopes can be determined by solving the equation of the critical moisture content. For the declining cohesive slopes, first, the cohesive soil having the cohesion and internal friction angle is replaced by only having the equivalent internal friction angle of the cohesionless soil according to the principle of the equal strength, then, the critical moisture content can be determined according to the relationship of the equivalent internal friction angle and the moisture content of the declining cohesionless.
With hydrochloric acid as the source of pollution, with laterite as the pollution soil, the shear strength and micro-structural characteristics of acid pollution laterite are studied by direct shear test. The results shown that, the shear strength and microstructure characteristics of acid pollution laterite are affected acid concentration and pollution time. The shear strength and indexes of acid pollution laterite decrease in general with the increase of acid concentration and the extension of the specimen pollution time, the shear strength and indexes exist a minimal value at lower concentration and shorter pollution time, the shear strength and indexes exist a great value at higher concentration and longer pollution time, the corresponding microstructure images present to the characteristics of compactness, roughness, color, texture.
Through indoor artificial rainfall test on the model slope of the laterite, the soil tests on samples of different parts of the model slope of laterite were carried out in the end of rainfall. According to the test results, the changes of the water content, the grain composition and the shear strength of the laterite in the model slope were analysed. The results showed that the effect of rainfall caused the water content of the laterite in the model slope to increase, and the altitude of the model slope was lower, the water content of the laterite in the model slope was higher. The effect of rainfall led to the density of the laterite in the model slope to decrease gradually when the altitude of the model slope was lower gradually. The grain composition exhibited that the silt content was increased and the clay content was reduced with the decrease of the model slope altitude. Based on analysing the variation of the water content, density and grain composition in the laterite of the model slope under the effect of rainfall, the changes of the shear strength of the laterite in the model slope were studied, further the changes of the cementatory characteristics of the laterite in the model slope were analysed under the effect of rainfall.
The migration characteristics of iron ions in laterite in water can reflected by change characteristics of iron ion concentration in water solution. Its migration ability depends on itself features of laterite and the effect of external environment. The results show that, the migration ability of iron ion in laterite were weakened with increasing of compaction energy and extending of immersion times, were strengthed with increasing of moisture content and temperature. The effect of compaction energy is least, the effect of temperature is maximum, the effect of moisture content is between them. Its migration process is that iron ion of adsorption in laterite particles surface were dissolved and migrated into process of the water solution. Its migration mechanism can explained from water environmental balance and temperature balance and ion concentration balance. The results changed the migration characteristics of iron ion in laterite at different influencing factors.
s. The microstructure characteristic of compacted laterite with acid contamination was researched by means of electronic microscope scanning and microstructures image analysis in which the hydrochloric acid was used as pollutant and the acid concentration and curing history of samples were taken into account. It shows that acid pollution significantly influences the microstructure of laterite in which with more acid concentration and longer pollution times, the microstructure images behave lower compaction, blur particle edges, dissolution cement among particles, gluing coatings parceling particles, pores among particles and darker gray color. The corresponding parameters of the microstructure behave different properties in which with longer pollution times of samples, there is a maximum of porosity, girths of particles increase, number of particles decreases, the circularity of particles is not obvious, the directionality and the fractal dimension vary with magnification of the images and with more acid concentration, the girths and porosity increase, the circularity and fractal dimension decrease, the particle number and the directionality vary with the magnification of images. The result shows that the mechanism of the effect of acid contamination on laterites micro structures is that the acid erodes its particles and the cement among particles.
The reservoir bank instability is the outcome combined the action of the external factors with the action of the internal factors. The limit equilibrium analysis, the strength reduction finite element method, the saturated/unsaturated seepage coupling and so on were applied to analyze the reservoir bank stability. The condition analogy graphical solution methods, the mathematical analysis method, the balanced cross-section method and so on were applied to forecast the reservoir bank stability. The reservoir bank instability mechanism depends on the physical action, the chemical action and the mechanical action of the water in the reservoir bank rock and soil. At present, the drainage measure, the cutting slope and reducing load measure, the retaining and supporting measure , the anti-slide piles measure and so on have been widely used to control the reservoir banks instability. Aiming at the research status of the reservoir bank instability, the problems in study and the suggestions for future work are pointed out in this paper.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.