复杂深海工程地质原位长期监测系统研发与应用  

Development and application of long-term in situ monitoring system for complex deep-sea engineering geology

作　　者：孙志文 贾永刚[1,2] 权永峥 郭秀军 刘涛[1,2] 孟庆生 孙中强[1,2] 李凯 范智涵[1,2] 陈天 唐浩儒 SUN Zhiwen;JIA Yonggang;QUAN Yongzheng;GUO Xiujun;LIU Tao;MENG Qingsheng;SUN Zhongqiang;LI Kai;FAN Zhihan;CHEN Tian;TANG Haoru(College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering(MEGE),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：《地学前缘》2022年第5期216-228,共13页Earth Science Frontiers

基　　金：国家自然科学基金重点项目(41831280);中国工程科技发展战略海南研究院重大咨询研究项目(21-HN-ZD-02);国家自然科学基金国家重大科研仪器研制项目(41427803)。

摘　　要：海底滑坡、浊流等深海底地质灾害严重威胁海洋工程安全,是国家深海开发亟待解决的风险问题。为避免深海海底地质灾害对海底工程造成危害,解决深海海底地质灾害监测预警的难题,我们研发了一套复杂深海工程地质原位长期监测系统。该系统通过声学、电阻率、超孔隙水压力等方法监测深海海底沉积物的物理力学性质变化,实现了对深海海底地质灾害的监测和预警。该系统主要包括海床基搭载平台、监测系统、通信控制系统、供电系统等。其中监测系统主要通过原位长期监测海底沉积物的电阻率、声学、超孔隙水压力等的变化来获取海底沉积物的物理力学性质变化;通信控制系统可以实现海底到海面,再到陆地的双向通信和数据传输。其中供电系统通过独特设计的海水电池工艺,可以满足该系统在海底长期工作一年的电量需求。复杂深海工程地质原位长期监测系统已完成了近海测试,并搭载“海洋地质六号”“东方红三号”“张謇号”等科考船在南海进行了多次远海海试,获取了丰富的实测数据。电阻率监测系统采用温纳法滚动测量,测得的水土界面位置平均电阻率为0.207Ω·m。超孔隙水压力监测系统采用开放式结构的压差式光纤光栅孔压测量方法,监测到孔压观测的4个标志性阶段:(1)贯入过程引起的超孔隙水压力累计,峰值为34.942 kPa,历时0.182 h;(2)贯入完成后累积的超孔隙水压力衰减,衰减到9.973 kPa,历时为0.810 h;(3)环境应力引起的超孔隙水压力实时响应,超孔隙水压力的变化范围为8.327~14.384 kPa;(4)残余孔隙水压力平均值为11.150 kPa。声学监测系统采用两个一发三收模式,测量的海水平均声速为1 533 m/s,测量的海底沉积物自上而下的平均声速依次为1 586、1 587、1 784、1 735、1 831 m/s。复杂深海工程地质原位长期监测系统的成功研制将显著提升目前海�Geohazards such as submarine landslides and turbidity currents are an urgent safety issue to be solved in marine engineering during national deep sea development.To avoid such risks and achieve geohazard monitory and early warning,we develop an in-situ monitory system for complex deepwater engineering geology(SEEGeo),using resistivity,acoustic and pore pressure monitoring to monitor the physical and mechanical changes in deep seabed sediments.This monitoring system mainly includes the seabed carrying platform,monitoring system,communication control system,and power supply system.The monitoring system performs long-term in-situ monitoring of resistivity,acoustic and pore pressure changes in seabed sediments;the communication control system is responsible for communication and data transmission from seabed to sea surface then to land;and the power supply system provides power for one year of long-term operation on the seabed via an unique seawater battery process.So far,SEEGeo has completed the offshore test and carried out multiple sea trials in the South China Sea on board scientific research ships(e.g.,“Marine Geology No.6”,“Dongfanghong No.3”,“Zhang Jian”),and collected large amounts of survey data.For example,using Wenner method,resistivity monitoring obtained an average resistivity of 0.207Ω·m at the water-soil interface location.Super excess pore pressure monitoring,using open-structured optical fiber-based differential pressure sensing,observed four landmark stages:1)pressure accumulation during penetration(up to 34.942 kPa over 0.182 h);2)pressure decay after penetration(down to 9.973 kPa over 0.810 h);3)real-time response to environmental stress(pressure change between 8.327-14.384 kPa);and 4)residual pressure(average 11.150 kPa).And acoustic monitoring,adopting two sets of one transmit-three receive setup,obtained a seawater average sound velocity of 1533 m/s,as well as average sound velocities of 1586,1587,1784,1735 and 1831 m/s in seafloor sediments from the top to the bottom layers.The s

关 键 词：海底地质灾害 物理力学性质 原位观测 声速 电阻率 孔隙压力 

分 类 号：P714[天文地球—海洋科学] P738[环境科学与工程—环境科学] X145