深海采矿中不同成分底质对羽流触发的影响  

The impact of different substrates compositions in deep-sea mining on triggering plume

作　　者：金小栋 陈旭光 刘金忠 刘茜茜 金帅 JIN Xiaodong;CHEN Xuguang;LIU Jinzhong;LIU Xixi;JIN Shuai(College of Engineering,Ocean University of China,Qingdao 266404,China;School of Civil Engineering and Architecture,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266404 [2]山东科技大学土木工程与建筑学院,山东青岛266590

出　　处：《海洋工程》2024年第4期150-163,共14页The Ocean Engineering

基　　金：中央高校基本科研业务费专项资助项目(202041004);山东省高等学校优秀青年创新团队资助项目(202042001);NSFC-山东联合基金资助项目(U1906234);国家杰出青年科学基金资助项目(52225107)。

摘　　要：深海采矿时羽流生成的主要原因在于采集过程中集矿车行走及采集对深海沉积物的扰动。沉积物受扰动后产生羽流,所以可以推断沉积物的物理性质可能对羽状流的生成存在影响。目前,通过已知研究发现,沉积物的抗扰动性主要由沉积物的强度所决定,而研究沉积物的强度必须先了解沉积物的结构。由于深海沉积物处在特殊深海高压含盐环境中,沉积物在沉降过程中形成了特殊的絮状连接结构,土颗粒之间产生胶结作用。胶结作用的强弱以胶结力的形式包含在沉积物所具备的黏聚力中,所以可以假定沉积物的胶结作用会影响沉积物的强度,进而影响羽流的触发。然而不同区域深海沉积物含水率及成分均有所差异,无法对沉积物的胶结作用进行定量分析,因此需通过试验探究不同成分底质的胶结作用强弱随底质成分的变化以及不同底质下羽流的触发规律。首先,选取碳酸钙质量分数与含水率作为变量,选取多种不同成分的模拟底质,探究胶结作用随土体成分的变化规律。其次,开展单射流冲击模拟底质模型试验,观测羽流的触发量与土体成分间的关系。研究结果表明:在射流冲击作用下羽流的触发量与冲击底质的胶结作用有关,模拟底质的胶结作用随着含水率的增大而减小,随着底质中碳酸钙质量分数逐渐增大,胶结作用呈现先增大后减小的趋势。研究结果将为集矿车采集过程中控制羽流触发以及水力采集参数优化提供理论依据。The primary cause of plume generation in deep-sea mining is the disturbance of sediment caused by the movement of mining trucks and collection during the collection process by the mining vehicle and collection activities.Sediment disturbance leads to the formation of plume,suggesting that the physical properties of sediment may influence plume generation.Currently,research indicates that the resistance to disturbance of sediment is primarily determined by its strength,which necessitates an understanding of sediment structure.Due to the unique deep-sea,high-pressure,and saline environment where deep-sea sediments are located,sediments form a peculiar flocculent connection structure during settling,with interparticle cementation.The strength of cementation is encapsulated in the sediment’s cohesive strength,suggesting that sediment cementation may influence sediment strength and thus plume triggering.However,deep-sea sediment compositions vary,with differences in water content and components,making quantitative analysis of sediment cementation challenging.Therefore,experimental investigation is needed to explore the variation in cementation strength of different substrates compositions and the triggering patterns of plume under different sediment components.Firstly,calcium carbonate content and water content are selected as variables,and various simulated substrates are chosen to investigate the variation in cementation with soil composition.Secondly,experiments are conducted using a single jet flow impact simulation substrate model to observe the relationship between plume triggering and soil composition.The results indicate that plume triggering under jet flow impact is related to the cementation of the impacted substrate.The cementation of simulated substrates decreases with increasing water content and shows a trend of initially increasing and then decreasing with increasing calcium carbonate content in the substrate.These findings provide a theoretical basis for controlling plume triggering during mining veh

关 键 词：深海采矿 羽流 深海沉积物 胶结作用 单射流冲击 

分 类 号：P744[天文地球—海洋科学]