风暴过程中泥质海岸的孔压响应——以舟山朱家尖海域为例  

Pore pressure response of silt seabed during storms-taking Zhoushan Zhujiajian sea area as an example

作　　者：侯衍凯 薛凉 梁天阳 单红仙[1,2] HOU Yankai;XUE Liang;LIANG Tianyang;SHAN Hongxian(Ocean University of China,Qingdao 266100,China;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Qingdao 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]山东省海洋环境地质工程重点实验室,山东青岛266100

出　　处：《海洋湖沼通报》2024年第2期62-70,共9页Transactions of Oceanology and Limnology

基　　金：国家自然科学基金(41877223)。

摘　　要：海床沉积物中的孔隙水压力对水动力变化反应敏感,调查不同海况下沉积物中的孔隙水压力响应情况对研究海床的失稳破坏,海底边界层的动态演化具有重要意义。在浙江舟山朱家尖海域采用孔隙水压力监测系统记录了台风利奇马前后观测区水动力条件及海床沉积物孔隙水压力在海床下1、3、5、7 m处的动态变化过程。监测数据显示,海床沉积物孔隙水压力的变化受静水压力及沉积物性质影响,短期内对波浪作用有明显响应。台风期间,水动力大幅增强,有效波高可达平静海况下的5倍以上,浅层1 m处沉积物超孔隙水压力震荡幅值可达1~2 kPa,超孔压值的变化与波浪强度具有很强的一致性。波浪荷载作用于海床沉积物过程中波压力有明显振幅衰减,在浅层1 m处其衰减可达70%以上,在1 m以下波浪的影响几乎可以忽略。探杆止位盘的影响是孔压振幅衰减的重要原因,除此之外,海床沉积物中气体的存在及海床浅层活动性淤泥层与波浪的相互作用能显著减弱波浪荷载对海床孔隙水压力的影响,是波浪能量消耗的重要因素。The pore water pressure in seabed sediments is sensitive to hydrodynamic changes,and investigating the response of pore water pressure in sediments under different sea conditions is of great significance to the study of seabed instability and dynamic evolution of seabed boundary layer.In the sea area of Zhoushan Zhujiajian,Zhejiang Province,the dynamic changes of the hydrodynamic conditions and the pore water pressure of seabed sediments at lm,3m,5m and 7m below the sea bed before and after typhoon Lekima were recorded by using the pore water pressure monitoring system.The monitoring data showed that the variation of pore water pressure in seabed sediments was affected by hydrostatic pressure and sediment properties,and had obvious response to wave action in short term.During the typhoon,the hydrodynamic force was greatly enhanced,and the effective wave height could reach more than 5 times of that under the calm sea condition.The oscillation amplitude of the excess pore water pressure in the sediment at the shallow lm layer could reach 1-2 kPa,and the change of the excess pore pressure value was strong consistently with the wave strength.In the process of wave load acting on seabed sediment,the wave pressure had obvious amplitude attenuation,and the attenuation could reach more than 70%at the shallow layer of 1 meter.The influence of waves could be almost ignored below l meter.The influence of rod stop plate was an important reason for the attenuation of pore pressure amplitude.The presence of gas in seabed sediments and the interaction between shallow active silt layer and waves could significantly reduce the influence of wave load on seabed pore water pressure,which was an important factor of wave energy consumption.

关 键 词：原位观测 孔隙水压力 利奇马 振幅衰减 

分 类 号：P715.9[天文地球—海洋科学]