The impact of structure on the undrained shear strength of cohesive soilsBojana Dolinar
, Ludvik Trauner
, 2007, izvirni znanstveni članek
Opis: The relationship between the undrained shear strength and the water content ofcohesive soils can be described with a two parameter non-linear function. Parameter a is the water content at the undrained shear strength su=1 kPa, andb is the slope of the linear function which represents the ratio between the water content logarithm and the undrained shear strength logarithm. These parameters depend mainly on the type and amount of clay minerals in the soils,the particle sizes and shapes, their arrangements, the forces between the clay particles, and the chemical composition of the pore water. The impactof quantity, type and size of clay grains on the water content at a uniform undrained shear strength in different soils has been studied previously, whilst the impact of structure is less understood. Particle associations and arrangements (i.e. fabric), and the interparticle forces determine the structure of soil. This paper focuses on an investigation of therelationship between water content and undrained shear strength in kaolinite samples with different structures. The various arrangements of clay particles that resulted from the changed of interparticle forces were obtainedby salt addition (NaCl). Microfabrics of wet kaolinite samples were studied using a field emission scanning electron microscope. The results showed that clay structure exerts a strong influence on the relationship between the quantity of water and undrained shear strength. This was reflectedin the values of both soil-dependent parameters, a and b. Values of parameter a varied between 39.16% and 62.96%, and b between 0.100 and 0.139, for well crystallized kaolinite with salt concentrations of 0- 175 mmol/l. Forpoorly crystallized kaolinite with salt concentrations of 0-300 mmol/l, thevalues of a range between 46.96% and 100.30%, and b between 0.090% and 0.148%.
Ključne besede: geomechanics, clay, kaolonite, structure, fabric, undrained shear strength
Objavljeno: 31.05.2012; Ogledov: 1468; Prenosov: 73
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