快速沉积作用对海底滑坡的贡献机制及影响因素研究  

Contribution of rapid sedimentation to submarine landslides and its influencing factors

作　　者：李正辉 杨迎 朱超祁 贾永刚[1,3] 寇海磊 LI Zhenghui;YANG Ying;ZHU Chaoqi;JIA Yonggang;KOU Hailei(College of Environmental Science and Engineering,Ocean University of China,Qingdao,Shandong 266100,China;College of Engineering,Ocean University of China,Qingdao,Shandong 266100,China;Shandong Provincial Key Laboratory of Marine Environmental Geological Engineering,Qingdao,Shandong 266100,China)

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100 [2]中国海洋大学工程学院,山东青岛266100 [3]山东省海洋环境地质工程重点实验室,山东青岛266100

出　　处：《岩石力学与工程学报》2023年第5期1225-1236,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金重点项目(41831280);青岛海洋国家实验室开放基金项目(MGQNLM-TD201808)。

摘　　要：众多海底滑坡都与快速沉积作用相关,然而,对海底滑坡的贡献机制以及影响因素缺乏系统研究。通过收集与快速沉积作用相关的海底滑坡相关案例,归纳和总结了海底滑坡基本特征。在此基础上,阐明了快速沉积作用触发海底滑坡机制,并给出在ABAQUS中的实现方法,最后对快速沉积作用触发海底滑坡的影响因素进行系统分析。研究结果表明:快速沉积作用导致海底地层超孔隙水压力累积,造成地层有效应力和强度增长减缓甚至降低,形成类似于“低重力场”环境,使海底斜坡在抵御地震、水合物分解、底辟等地质作用下能力减弱。此外,随着海底斜坡坡度的增加,沉积速率的加快,沉积物压缩性的增大,海底斜坡更易出现短滑动周期的浅层破坏。在低沉积速率,沉积物高压缩性条件下,也会导致海底地层欠固结,最终对海底斜坡稳定性产生不利影响。Many submarine landslides are associated with rapid sedimentation.However,relevant research on the contribution of rapid sedimentation to submarine landslides and its influencing factors wer he character of submarine landslides associated with rapid sedimentation was firstly summarized by analyzing relevant cases.Subsequently,the mechanism of submarine landslides triggered by rapid sedimentation was clarified and the corresponding implementation method based on ABAQUS was provided.Finally,the influencing factors of submarine slope instability caused by rapid sedimentation were discussed systematically.The results show that the generation of excessive pore pressure caused by rapid sedimentation will make the effective stress and strength of sediment grow slowly and even decrease.A low gravitational field formed by rapid sedimentation makes submarine slope easier to failure when it suffers from some geological processes like earthquake,hydrate dissociation and diaper.In addition,a short-period shallow slide is more likely to occur when the submarine slope is with a steep gradient,sediment with high compressibility and a depositional environment with high sedimentation rate.It is noted that sediment with high compressibility will also lead to a under-consolidated stratum even if the sedimentation rate is low,which is unfavorable for stability of submarine slopes.

关 键 词：海洋地质灾害 海底滑坡 快速沉积作用 滑坡特征 斜坡稳定性 超孔隙水压力 

分 类 号：P67[天文地球—海洋地质]