Study On Uniaxial Strength Of Methane Hydrate Sediments

In this study, a low-temperature high-pressure triaxial apparatus suitable for hydrate strength testing developed by Dalian University of Technology was used to uniaxial strength research of synthetic methane hydrate sediments. Basic on the experimental results of methane hydrate deposits under uniaxial compression.the mechanical parameters were analyzed.The main research work are as follows:Basic on triaxial compression experiments in soil mechanics,,we designed the experimental scheme of the uniaxial compression of methane hydrate sediments according to the features of gas hydrates low-temperature high-pressure triaxial apparatus. Included: methane hydrate formation, sediment sample preparation and compression test process.We observed the φ40,φ60and φ8O of stress-strain curves, obtained the uniaxial deformation properties of methane hydrate sediments, and figured out the relationship between the deformation and temperature, strain rate and porosity.The effect of temperature and strain rate on initial yield strength of φ40and φ60methane hydrate sediments were analyzed. The functional relationship between initial yield strength and temperature and between initial yield strength and strain rate were figured out for φ40and φ60methane hydrate sediments respectively. A prediction equation of initial yield strength about temperature and strain rate was developed. The sensitivity of initial yield strength to temperature and strain rate under different porosity was discussed.The effect of temperature, strain rate and porosity on initial yield strain of methane hydrate sediments were analysed.Basis on the initial yield strain and initial yield strength, the initial yield modulus was analysed. The functional relationship between initial yield modulus and temperature and between initial yield modulus and strain rate were figured out for φ40and φ60methane hydrate sediments respectively. A prediction equation of initial yield strength about temperature and strain rate was developed.The functional relationship between peak strength and temperature and between peak strength and strain rate were figured out for φ40and φ60methane hydrate sediments respectively. A prediction equation of peak strength about temperature and strain rate was developed. The effect of porosity on peak strength was discussed.