| Laterite its special physical, hydrological and mechanical properties different from ordinary clay, due to rapid economic development in the distribution of laterite construction increasing, stable nature of the influence of special projects laterite project construction safety has become increasingly prominent. Kunming Kunming Changshui Airport is located in eastern plateau karst plateau lake basin sub-region, northeast of Kunming Basin, the area red clay, laterite types and causes of more complex nature of the works, for airport security and stability of all types of buildings greater impact. As the traditional red laterite theoretical shortcomings and deficiencies, the results of the geotechnical investigation airport laterite project areas such as sandstone and shale and basalt rock by silicate laterite role in the formation of a rough classification simply named "Red Clay", failed to objectively a true reflection of the type of laterite causes and engineering features that make the results of geotechnical engineering investigation airport flawed.Special laterite aggregate structure, it exhibits less dense natural, natural water content, saturation, porosity is relatively large, liquid limit, plastic limit high, resulting in physical clay, water, soil physical properties have soft features, mechanics they exhibit the characteristics of the nature of sandy silt, making laterite engineering geological characteristics very special. Laterite laterite aggregate structure is a direct result of the action, laterite aggregate of particle size, the number of content, as well as the aggregate number of other components are the basic structural unit of the special factors affecting the engineering properties of clay. Because there are serious differences between the academic and the classification of the causes of clay, laterite particle composition analysis of a lack of systematic experimental protocols existing norms for the lack of objective scientific evidence on laterite particle composition test requirements to enable analysis of the laterite particle discrete components results too, no rules to follow, more not accurately reflect the aggregate laterite particle size, aggregate quantity and structure of the unit body content. A long water airport laterite genetic types of new laterite causes theory instructor operator will chang established in different dispersant types, at different concentrations paper focuses on long water airport sandstone and shale (G2d) and basalt (P2e) residual laterite particle size composition the size composition and grain size variation characteristic value system components analyzed, objective scientific reveal various dispersants for different types of effects on clay, laterite difference and the main features of different types of particle composition, for further analysis of the integrated system of research on laterite engineering geological characteristics of the foundation.Kunming Changshui Airport by sandstone and shale and basalt laterite role in the formation of the corresponding residual clay, can be divided into the typical clay, massive clay, shot laterite according to the degree of residual effect of clay. Sandstone and shale laterite residual effect due to strong erosion, leaving only massive laterite, granular clay. The Permian Emeishan basalt in the system residual laterite profile preserved its typical clay, massive laterite, granular laterite are preserved. In this paper, four kinds of dispersants on the five categories of Comprehensive test soil samples were granulometric composition at different concentrations.In this paper, the particle size composition of the five classes of laterite samples were analyzed test results:(1) dispersing agent under conditions not add sand shale and basalt laterite respective residual particles are mainly concentrated in the group, indicating that massive laterite and laterite soil granular particles very uneven, with the main body of powder pellets state, that residual laterite different Laterization phase dispersion effect in terms of forming their commonality also has properties; upon removal of organic matter in soil containing organic matter have a certain effect (2) hydrogen peroxide is used, but the effect is poor when used alone; selection When the dispersant is used alone, it should gradually abandon the use of ammonia and hydrogen peroxide, but may be considered in combination with other commonly used dispersants; (3) This 4 dispersants common one thing in common, that is, within a certain range of dispersion with dispersing agents increasing concentration enhanced when the concentration reaches a certain value after the dispersion effect a qualitative change, to achieve the best dispersion range and optimal dispersion, and then gradually decreased dispersion; (4) the same soil samples with different concentration dispersion agent, the granule content was greatly affected and may reach different naming, so that there are some differences in naming and engineering properties of red clay of its actual situation, it is essential the type and concentration of dispersant on the particle size analysis tests; (5) Residual laterite and sandstone and shale aggregate structure of basalt residual laterite substance is formed by a rubber-based cement powder group, with false aggregates and water stable aggregates of water-resistant properties; (6) granular laterite proposal 3%-5% sodium hexametaphosphate as a dispersing agent, typical and massive laterite recommend the use of 6%-8% sodium hexametaphosphate as a dispersing agent is dispersed better; concentration value (7) specification recommends dispersant, Most of the test results did not reach the peak, indicating laterite clayey soil as a special particularity in terms of size composition, different from the general clay, should be given differential treatment. |
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