基于深海矿车-稀软土相互作用的矿车触底过程分析  

Analysis of the bottoming process through deep-sea mining vehicle-soft sediment interaction

作　　者：李宗晏 陈旭光 刘学麟 刘茜茜 丁聪 LI Zongyan;CHEN Xuguang;LIU Xuelin;LIU Xixi;DING Cong(Engineering College,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266100

出　　处：《海洋工程》2024年第5期178-190,共13页The Ocean Engineering

基　　金：国家杰出青年科学基金资助项目(52225107);NSFC-山东联合基金资助项目(U1906234);国家重点研发计划课题资助项目(2021YFC2801503);中央高校基本科研业务费专项(202041004)。

摘　　要：多金属结核赋存在深海5.0 km左右的平原区域,该区域的稀软沉积物含水率高、承载力低。深海采矿车在触底过程中,矿车下方稀软沉积物受到冲击后易发生扰动破坏,从而极易引发矿车沉陷,这将严重影响矿车的正常作业,甚至会导致停机。矿车是否沉陷与其触底后的应力分布形式密切相关,但尚无理论对其进行分析。通过开展采矿模型车不同触底速度下的触底试验,揭示了矿车触底后下方土体竖向应力随时间的变化规律及分布范围。在传统理论基础上,推导并验证了一种考虑履齿影响的竖向应力值的理论公式。研究发现,触底后下方土体的应力值会快速增长并趋稳定,且达到稳定应力值所需时间与触底速度成反比。随着触底速度增大,矿车下方应力泡形状会从平滑单峰向单峰两侧有平台的形状变化,车体正下方的应力传播得最远。相对于平板,履齿板应力影响深度显著增加。经误差分析,改进的理论公式比传统理论与试验结果吻合效果更好,提升了深海矿车触底后应力计算精度。文中研究围绕矿车触底后的海床应力分布进行了一系列讨论,可为深海矿车低扰动、防沉陷设计提供理论参考。Polymetallic nodules are distributed in the deep-sea plains at around 5.0 km depth,where the soft sediments have high water content and low bearing capacity.When a deep-sea mining vehicle touches down,the soft sediments under the vehicle can be easily disturbed and lead to vehicle sinking,which will significantly affect the normal operation and may even cause the machine to shut down.The sinking of the mining vehicle is closely related to the stress distribution under the vehicle after touchdown,but there is no theoretical analysis on this.By conducting bottoming test on a mining vehicle model at different bottoming speeds,the study reveals the variation of the vertical stress under the vehicle with time and the stress distribution range.Based on the traditional theory,a theoretical formula considering the effect of the crawler track has been derived and verified.The research found that the stress value under the vehicle will rapidly increase and stabilize,and the time required to reach the stable stress value is inversely proportional to the bottoming speed.As the bottoming speed increases,the shape of the stress bulb under the vehicle changes from a smooth single peak to a single peak with platforms on both sides,and the stress propagation distance directly under the vehicle body is the farthest.Compared to a flat plate,the stress influence depth of the crawler track plate is significantly increased.Error analysis shows that the improved theoretical formula has better agreement with the experimental results than the traditional theory,improving the accuracy of stress calculation after the deep-sea mining vehicle touches down.This study discusses the seabed stress distribution after the mining vehicle touches down,which can provide theoretical reference for the design of low-disturbance and anti-sinking deep-sea mining vehicles.

关 键 词：深海采矿车 触底速度 应力分布 稀软沉积物 应力云图 

分 类 号：P751[交通运输工程—港口、海岸及近海工程]