Mechanical properties of methane hydrate- bearing-sediments （MHBS） are basic parameters for safety analysis of hydrate exploration and exploitation. Young＇s modulus, cohesion, and internal friction angle of hydrate...Mechanical properties of methane hydrate- bearing-sediments （MHBS） are basic parameters for safety analysis of hydrate exploration and exploitation. Young＇s modulus, cohesion, and internal friction angle of hydrate- bearing sediments synthesized in laboratory, are investigated using tri-axial tests. Stress-strain curves and strength parameters are obtained and discussed for different compositions and different hydrate saturation, followed by empirical expressions related to the cohesion, internal friction angle, and modulus of MHBS. Almost all tested MHBS samples exhibit plastic failure. With the increase of total saturation of ice and methane hydrate （MH）, the specimens＇ internal friction angle decreases while the cohesion increases.展开更多
By comparing the dynamic responses of saturated soil to Biots and Yamamotos models, the properties of the two models have be pointed out. First of all, an analysis has been made for energy loss of each model from the ...By comparing the dynamic responses of saturated soil to Biots and Yamamotos models, the properties of the two models have be pointed out. First of all, an analysis has been made for energy loss of each model from the basic equations. Then the damping of elastic waves in coarse sand and fine sand with loading frequency and soils parameters have been calculated and the representation of viscous friction and Coulomb friction in the two models has been con-cluded. Finally, the variations of loading wave damping and stress phase angles with water depth and soils parameters have been obtained as loading waves range in ocean waves.展开更多
基金supported by the National Natural Science Foundation of China (11102209 and 11072245)the National High Technology Research and Development Program of China (863)the Key Program of Chinese Academy of Sciences (KJCX2-YW-L02)
文摘Mechanical properties of methane hydrate- bearing-sediments （MHBS） are basic parameters for safety analysis of hydrate exploration and exploitation. Young＇s modulus, cohesion, and internal friction angle of hydrate- bearing sediments synthesized in laboratory, are investigated using tri-axial tests. Stress-strain curves and strength parameters are obtained and discussed for different compositions and different hydrate saturation, followed by empirical expressions related to the cohesion, internal friction angle, and modulus of MHBS. Almost all tested MHBS samples exhibit plastic failure. With the increase of total saturation of ice and methane hydrate （MH）, the specimens＇ internal friction angle decreases while the cohesion increases.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 40176027).
文摘By comparing the dynamic responses of saturated soil to Biots and Yamamotos models, the properties of the two models have be pointed out. First of all, an analysis has been made for energy loss of each model from the basic equations. Then the damping of elastic waves in coarse sand and fine sand with loading frequency and soils parameters have been calculated and the representation of viscous friction and Coulomb friction in the two models has been con-cluded. Finally, the variations of loading wave damping and stress phase angles with water depth and soils parameters have been obtained as loading waves range in ocean waves.
