Settlement Analysis for An Embankment Considering Visco-Elasto-Plastic Characteristics

—In the paper.a visco-elasto-plastic constitutive model and a method for determining modelparameters for soft clay are presented.In this model total strain of soft clay is assumed to be divided intothree parts:instantaneous elastic.visco-elastic and visco-plastic.The characteristics of instantaneous andvisco-elastic deformation of soft clay are simulated by Merchant's model.the plastic is by a model withtwo yield surfaces.And related constitutive equation is conducted,A number of stress-controlled triaxialtests are performed to calculated the model parameters The visco-elasto-plastic model is used for analysisof the displacement of an embankment on soft ground by use of three-dimensional finite element method.The predicted settlements agree well with the measured data.It is indicated that the viscous characteristicsshould be taken into account in deformation analysis for soft clay.     

水平荷载下海上风机单桩基础桩土相互作用研究

海上风电作为一种清洁绿色的能源越来越受到人们的关注,海上风机会承受风、浪、流等水平荷载的作用,因此水平荷载下海上风机单桩基础桩土相互作用一直是人们研究的热点。本文对水平荷载作用下海上风机单桩基土相互作用进行研究,通过ABAQUS有限元数值分析软件建立桩土模型。结果显示:桩顶水平极限位移约为11.25cm,海床面以下1~5m范围为桩身弯矩和桩身mises应力较大的区段;随着桩顶水平位移的逐渐增大,桩身挠曲逐渐向深处发展,桩体位移零点位置逐渐向下;桩体的水平位移会对桩侧土体产生挤压作用,这种挤压作用会使土体塑性屈服区逐渐向下发展,土体水平位移呈半圆形放射状分布,浅层土体mises应力产生非对称分布。     

An Analysis on Limit Load for Corroded Submarine Pipelines

1 .Introduction Submarine pipelines are one of the safest and the least environmentally disruptive means for ma-rine gas or oil transport . With the development of exploitation of submarine oil or gas ,the safety ofsubmarine pipelines has becomethe major …     

A Method for the Damage Detection of Pile Foundation in High-Pile Wharf Based on A Curvature Mode Deletion Model

China Ocean Engineering - As the top of the pile foundation in high-pile wharf is connected to the superstructure and most of the pile bodies are located below the water surface, traditional damage...     

Dynamic Analysis for the Global Performance of An SPM-Feeder-Cage System Under Waves and Currents

In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodynamics coefficients of the vessel are calculated by using a 3D diffraction/radiation panel program. First- and second-order wave forces are included in the calculations. Morison equation is used to compute the drag force on line elements representing the net. Drag coefficients are determined at every time step in the simulation considering the relative normal velocity between the structural elements and the fluid flow. The dynamic response of the coupled system is analyzed for various environments and net materials. The results of the study show the effects of solidity ratio of the net and vertical positions of the cage on the overall dynamic response of the system, confirming the viability of this type of configuration for future development of offshore aquaculture in deep waters.     

波浪作用下粉质土海床累积孔隙水压力简化分析

波浪引起的孔隙水压力直接影响海床地基稳定性,而累积孔隙水压力是细颗粒弱粘性粉质土的主要响应形式。针对在海岸和近海广泛分布的粉质土,基于一维固结理论,采用更适于描述粉质土动力特性的双曲线型孔隙水压力发展模式作为源项,推导相应的有限差分格式,并在MATLAB环境下进行编程求解,给出波浪作用下粉质土海床累积孔隙水压力响应的简化分析方法。以黄河三角洲为背景的算例显示,本文所给的模型和计算方法高效、易行,可为相关的海岸与海洋工程设计提供理论参考和技术支持。     

A Method Based on Multi-Body Dynamic Analysis for A Floating Two-Stage Buffer Collision-Prevention System Under Ship Collision Loads

China Ocean Engineering - The collision of ships poses a great threat to the piers in navigable waters. The kinetic energy of the moving ship can be consumed not only with the structural...     

一种海洋浮游植物定量研究分析方法——Uterm(¨)ohl方法的介绍及其改进

对国际上通用的浮游植物定量生物学基础研究方法——Utermhl方法的应用进行了介绍,并对此方法的不足之处和误差来源进行了分析.在此基础上,对误差的统计方法提出进一步改进.同时,指出了我国现有海洋调查中浮游植物定量研究方法的不足之处,建议以Utermhl方法替代网采方法作为今后中国海洋浮游植物定量生物学研究的基本手段.