The effects of hydrate cement on the stiffness of some sands

Abstract

Cementing of sediment occurs naturally in many soils and weak rocks, during both the early and late stages of diagenesis. This paper reports the results of a series of resonant column tests carried out on a range of sand-sized geomaterials to explore the effects of different hydrate cement morphologies on the very small strain stiffness of the materials. It is shown that the proportion of void space filled by hydrate cement, cement location, sand size and grain shape all have a significant effect on shear modulus. The change in stiffness between different host materials is affected by the density, specific surface and grading of the geomaterial.

Parameters controlling stiffness and strength of artificially cemented soils

“…In the present research, it has been observed that the cement inclusion strengthens and stiffens the soil matrix, and that the amount of strengthening and stiffening is also a function of the soil matrix. The importance of soil grading, particle shape and D 50 on verysmall-strain stiffness of cemented sediments has been shown previously by Clayton et al (2010).…”

“…In the present research, it has been observed that the cement inclusion strengthens and stiffens the soil matrix, and that the amount of strengthening and stiffening is also a function of the soil matrix. The importance of soil grading, particle shape and D 50 on verysmall-strain stiffness of cemented sediments has been shown previously by Clayton et al (2010).For the Osorio sand-cement mixture, assembling the optimum fitting curves of the unconfined compressive strength (q u ) and initial shear modulus (G 0 ) with adjusted porosity/cement ratio allows a relationship for G 0 /q u to be determined as a function of ç/(C iv ) 1 : 0 (see equation (1) For the Porto silty sand-cement, assembling the optimum fitting curves of q u and G 0 with adjusted porosity/cement ratio (ç/(C iv ) 0 : 21 ) allows a unique relationship to be established for G 0 /q u (see equation (2) So specific relationships for G 0 /q u are found for the two soils. The Osorio sand has a higher G 0 /q u relationship than the Porto silty sand.…”

Relationship between Creep Property and Loading-Rate Dependence of Strength of Artificial Methane-Hydrate-Bearing Toyoura Sand under Triaxial Compression

“…An experimental method for performing triaxial compression tests on artificial methanehydrate-bearing sediment samples has been developed [12], and the mechanical properties of methanehydrate-bearing sediments have been partially clarified [13][14][15][16][17][18][19][20][21][22][23][24]. However, the time-dependent behaviors of methane-hydrate-bearing sediments have not been fully clarified, although they are thought to have great significance in predicting the long-term behaviors of sediment over a time scale of decades.…”

Critical state soil constitutive model for methane hydrate soil

“…[9] Note that the degree of these changes depend highly on hydrate morphology. For example, the rate of increase in small strain stiffness with increase in hydrate saturation is much greater in the cementing type compared to that in the pore filling type [e.g., Clayton et al, 2010;Priest et al, 2009]. The detailed explanation on modeling of mechanical behavior at larger strains with different morphologies is shown later.…”