防灾减灾工程学报2025，Vol.45Issue(6)：1371-1382,12.DOI:10.13409/j.cnki.jdpme.20250430046
孔隙压力与地震作用对富含水合物海底边坡稳定性影响研究
Study on Influence of Pore Pressure and Seismic Action on Stability of Hydrate-rich Submarine Slopes
摘要
Abstract
Natural gas hydrates(NGH)existing in shallow deep-sea sediments are regarded as a novel clean energy carrier.During phase transition,NGH generates a small amount of water and a large vol-ume of natural gas,which not only weakens the cementation between hydrates and soil particles but al-so generates excess pore pressure.Compared with the Nixon-Grozic modified model,a constitutive model further revised by incorporating gas compressibility parameters and a non-ideal gas equation of state produces excess pore pressure predictions that better reflect engineering practice.Additional seis-mic forces significantly affected the safety of hydrate-bearing slopes by altering the structural strength of the soil.Based on the infinite slope stochastic field theory,the positive promoting and negative re-straining effects of pore pressure variations and vertical seismic action on slope instability probability were systematically analyzed.Using the second hydrate trial-production reservoir in the South China Sea as a case study,the safety factors of the submarine slope were calculated under three conditions:ignoring excess pore pressure,applying the Nixon-Grozic modified model,and implementing the non-ideal gas modified model.The results indicated that as hydrate dissociation in the reservoir intensified,the slope safety factor declined progressively when excess pore pressure was not considered.When the Nixon-Grozic modified model and its non-ideal gas modified model were used for simulation,the slope safety factor demonstrated a non-monotonic trend of initially decreasing and then increasing,with predictions from the Nixon-Grozic modified model consistently lower than those from the non-ide-al gas modified model.Notably,when the spatial variability of the reservoir's mechanical parameters was considered,probabilistic analysis revealed a significant increase in slope failure probabilities,indi-cating that hydrate dissociation severely compromised slope reliability.关键词
水合物分解/海底边坡/稳定性/可靠性Key words
hydrate dissociation/submarine slope/stability/reliability分类
能源科技引用本文复制引用
XU Jitao,ZHU Haitao,JIANG Mingjing,LI Wenhao,ZHANG Peiyao,LI Yuying..孔隙压力与地震作用对富含水合物海底边坡稳定性影响研究[J].防灾减灾工程学报,2025,45(6):1371-1382,12.基金项目
国家自然科学基金项目(52378524)、天津市应用基础研究项目(22JCYBJC00640)资助 （52378524）
