南汇南滩波致海床响应与液化研究  

Study on seabed response and liquefaction induced by waves in the southern tidal flat of Nanhui,Shanghai

作　　者：张敬邦 范代读[1] 孟令鹏 崔明慧 徐昌伟[1] 涂俊彪[1] ZHANG Jingbang;FAN Daidu;MENG Lingpeng;CUI Minghui;XU Changwei;TU Junbiao(State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学海洋地质国家重点实验室,上海200092

出　　处：《海洋地质前沿》2025年第4期37-46,共10页Marine Geology Frontiers

基　　金：国家自然科学基金重点项目(42330411);上海市教委科研创新计划自然科学重大项目(2021-01-07-00-07-E00093);亚洲合作资金项目“长江三角洲与红河三角洲海洋地质环境与灾害合作研究”。

摘　　要：海床液化是海洋地质灾害中的一种常见现象,不仅会造成海床侵蚀,还会对区内海底管线、海洋设施等产生重大危害。目前,对海床液化机制研究大多基于室内物理模型实验,基于现场观测的研究较欠缺。本研究在南汇南滩进行了为期1个月的现场观测,利用固定平台的声学多普勒流速仪获得流速和水压等高频数据,并使用自制的孔隙水压力探杆获取海床土体不同深度的孔隙水压力数据。同时,分析了一次冬季大风事件期间孔隙水压力对波浪荷载的响应特征,计算了海床液化的深度。结果表明,孔隙水压力响应特征受潮位和波高的影响。总孔隙水压力响应的趋势受潮位影响,波致孔隙水压力响应的振幅受有效波高影响;研究区海床液化程度随深度的增加而降低,由于观测期间有效波高较低,液化深度仅为十几厘米。Seabed liquefaction is a common phenomenon in marine geological disasters,which not only leads to seabed erosion but also poses significant risks to subsea pipelines,marine facilities,and other structures in the area.At present,available studies on the mechanisms of seabed liquefaction is based mainly on indoor physical model experiments,and the field observations are very scarce.In this study,we conducted a one-month field observation at the southern tidal flat of Nanhui,Shanghai.An acoustic Doppler velocimeter was mounted at the fixed platform to obtain high-frequency data of flow velocity and water pressure.A self-made pore pressure probe was applied to collect pore pressure data at different depths of the seabed sediments.In addition,we analyzed the response characteristics of pore pressure to wave loading during a winter gale event and calculated the depth of seabed liquefaction.Results show that the characteristics of pore pressure response are affected by tidal level and wave height,of which the trend of total pore pressure response is affected by tidal levels,and the amplitude of wave-induced pore pressure response is affected by significant wave height.The degree of seabed liquefaction in the study area decreased with depth increase.Due to the relatively low significant wave height during the observation period,the liquefaction depth was only a dozen centimeters.

关 键 词：海床液化 孔隙水压力 有效应力 南汇南滩 滞后效应 

分 类 号：P736.2[天文地球—海洋地质]