摘要
海底边坡失稳会给人类造成巨大危害,部分海底边坡失稳案例被证实与水合物分解有关。由于海底条件的复杂性,人们很难直接观察水合物分解引起的海底边坡失稳过程。数值模拟可以相对准确地预测水合物分解可能引起的海底边坡失稳状况。通过选用基于ABAQUS软件的有限元强度折减法,模拟海底边坡失稳的过程并得到相应结果,分析了水合物分解程度、水合物带上覆厚度、边坡角度等因素对海底边坡稳定性的影响。结果表明,正常情况下,塑性区首先在坡脚区域出现并逐渐向上发展至坡顶;当水合物分解达到一定程度后,塑性区首先出现在水合物带,随后自水合物带向上发展至坡顶,并和随后在坡脚出现的塑性区形成贯通边坡的塑性带。水合物埋藏越深,越有可能造成大规模的滑坡;边坡角度高于15°时,水合物分解会急剧促进边坡失稳。
Hydrate dissociation is a significant factor causing submarine slope slide,which is dangerous to human operation.Due to the complex condition of seabed,it is hard to observe the process of slope slide directly.Numerical simulation is an effective approach to acquire some important parameters such as the slide area,slide scale,sliding distance and safety factors etc.Choosing shear strength reduction technique of the finite element based on the software of ABAQUS,we could not only simulate both the process and result of a slope slide,but also evaluate the influence of hydrate dissociation.By changing the parameters of modeling,the characteristics of seafloor can be considered.Of course,the inducing factor is the interaction between the structure of slope and hydrate dissociation.It can guide the hydrate exploitation process and avoid some possible problems by integration of the theoretical and simulation results.
作者
宋本健
程远方
李庆超
韩忠英
吕亚慧
SONG Benjian;CHENG Yuanfang;LI Qingchao;HAN Zhongying;LV Yahui(China University of Petroleum (East China ),Qingdao 266580,China)
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2019年第3期182-192,共11页
Marine Geology & Quaternary Geology
基金
国家重点研发计划“海洋水合物钻完井及安全监测技术”(2016YFC0304005)
国家重点基础研究发展计划(973计划)“海洋深水油气安全高效钻完井基础研究”(2015CB251201)
青岛海洋科学与技术国家实验室开放基金“天然气水合物开发储层失稳机制及控制技术研究”(QNLM2016ORP0212)
关键词
水合物分解
海底边坡
有限元
强度折减法
安全系数
hydrate dissociation
marine slope
the finite element
shear strength reduction technique
factor of safety
