Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Numerical Simulation of Multi-parameter Interaction between Track Plate ofDeep-sea Mining Vehicle and Seabed Sediments
Pengfei Sun1,2, Haining Lu1,2*, Jianmin Yang1,2, Mingyue Liu1,2, Shuang Li1,2
State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong UniversityYazhou Bay Institute of Deepsea SCI-TECH, Shanghai Jiao Tong University
1Shanghai, China 2Sanya, Hainan, China

12ABSTRACT

minerals needs to be mined at one time, and the crawling type hashigher stability than the floating type, the deep-sea mining vehicles
with deep diving depth, wide range of motion, strong operation ability
and crawling has become the core equipment for the development of
deep-sea minerals and other seabed resources (Leng, et al.2021).
Due to the characteristics of strong traction performance, lowgrounding specific pressure and high passing performance, most of thetraveling mechanisms of deep-sea mining vehicles are mainly trackplate types. Different from the floating ROV, the deep-sea mining
vehicle has a large weight in the water, and the seabed sediment has thecharacteristics of high water content, low bearing capacity, andextremely soft (Yamazaki, et al. 2005), mining vehicles operating on
the seabed will cause a large sinkage, and the sinkage of mining
vehicles will generate additional compaction resistance and soil
bulldozing resistance (Wang, et al. 2016), which will reduce thewalking performance of mining vehicles. Therefore, it is necessary tostudy the sinkage performance of the mining vehicle. On the other hand,existing literature shows that the surface of deep-sea sediments inmajor mining areas is mainly divided into three parts (Wu, et al. 2010):(1) Super soft zone: the surface is relatively soft, the soil is fluid plastic,
and the stability is poor, the provided shear strength is low;(2)transition zone: the middle layer has a higher shear strength, suitable
for mining vehicles to walk; (3) compact zone: the bottom layer has ahigher shear strength, but the additional resistance generated by a large
number of sinkage exceeds this layer the provided soil thrust, therefore,
needs to be controlled by the amount of sinkage of the mining vehicle
to obtain optimal traction. The track plate is a key component of thetraveling mechanism, and its mechanism parameters affect the overall
kinematic performance of the mining vehicle. Therefore, it is necessary
to study the influence of the track plate parameters and external force
on the sinkage performance, and to study the dynamic response of thesoil.
Passive earth pressure theory is widely used to predict the maximum
load that a track plate vehicle can support on the soil. By approximating
the vertical load applied by the rigid track plate on the soil as a beltload, based on the plastic limit equilibrium theory, the soil bearing
capacity formula is obtained (Wong, 2018). Due to several
simplification assumptions, this formula can only obtain approximate
results, and the interaction between equipment and sediments iscomplicated in practice. Most of the existing studies are based on

Deep-sea sediments have the characteristics of high water content,strong compressibility, low shear strength, and relatively soft. Mining
vehicles will experience substantial sinkage when operating on theseabed, and additional compaction resistance and bulldozing resistancewill directly affect the mining vehicle. walking performance, and it isnecessary to study the sinkage performance of mining vehicles.
Deep-sea mining vehicles usually use the track plate as the travelingmechanism, and the track plate is an important part of the track platesystem. It is significant to study the sinkage interaction between thetrack plate and the soil to study the sinkage performance of the mining
vehicle. Based on a 1000-meter undisturbed seabed soil sample
collected by a box sampler in a certain area of the South China Sea, thephysical and mechanical parameters of soil moisture content,composition, shear strength and compressive modulus in this area weremeasured by indoor geotechnical instruments. An elastoplastic soil
numerical model similar to that of undisturbed soil was established, andby designing different types of track plate, a coupled numerical modelof track plate-soil sinkage interaction was obtained. Based on the CEL
numerical method, the numerical simulation of the track plate sinkage
under different sinkage speed, loading rate, track plate shape and trackplate grouser structure parameters was carried out. The influence ofdifferent parameters on the sinkage of the track plate and the dynamic
response of the soil.

KEY WORDS: Deep-sea mining vehicle; Physical and mechanicalproperties of deep-sea sediments; Track plate sinkage; CEL numericalsimulation method

INTRODUCTION
With the increasingly poor terrestrial mineral resources and thecontinuous exploration of the ocean by human beings, the rich mineral
resources of the seabed are becoming the new focus of competition
among major economies in the world (Dai, 2010). Due to the harshenvironment in the deep-sea, the exploitation of resources must rely onunderwater robots for deep-sea operations. Since a large amount of49