Analysis of Angular Side Berthing Against a Rubber Cone Fender

This paper analyzes fender selection process in berth design and focuses on the case of a rigid berth with rubber cone fenders.Fender types and performance comparison methods are studied along with current numerical models.Berth design methods are analyzed with a focus on berthing energy calculation and fender selection.A new approach to determine the required fender capacity is suggested.A finite elements rubber cone model is tested and used in simulations of angular side berthing.Results show that the energy absorbed by the fender can be much higher than what can be calculated with the current berth design method.A new form for the expression of the energy that must be absorbed by the fender during angular berthing impact is suggested.     

码头系泊船舶缆绳线力的混沌解法

码头系泊船舶缆绳张力的理论计算对于缆绳的选取、系泊设备的设计、系泊方式、缆绳预紧力的确定,以及船级社规范的制订都有着重要的指导意义。文中对小波浪水域码头系泊船舶缆绳张力的计算建立了数学模型,引入混沌优化的方法对非线性系泊方程组进行了求解,其结果与实验结果对比有较好的一致性。     

基于船舶优先权的集装箱港口泊位分配问题

泊位作为港口的重要资源,它的有效管理对于港口有着重要意义。集装箱港口泊位分配问题（BAP）,实质是为到达集装箱港口的船舶安排最佳停靠位置与停靠时间。本文考虑到船舶动态到达的情况,以及实际操作中码头装卸效率对船舶在港作业时间和船舶优先权的影响,以最小化包括等待时间在内的船舶在港停留时间为目标,建立了基于船舶优先权的连续布置泊位分配模型。该模型是0-1混合整数规划模型,对于小规模问题,可采用商业优化软件求解,对于大规模问题,可设计遗传算法处理。算例分析表明,考虑了连续布置泊位分配问题的二维特性和船舶优先权,能够找到更符合实际的泊位分配方案。     

Prediction of hydrodynamic forces on a moored ship induced by a passing ship in shallow water using a high-order panel method

A three-dimensional high-order panel method based on non-uniform rational B-spline (NURBS) is developed for predicting the hydrodynamic interaction forces on a moored ship induced by a passing ship in shallow water. An NURBS surface is used to precisely represent the hull geometry. Velocity potential on the hull surface is described by B-spline after the source density distribution on the boundary surface is determined. A collocation approach is applied to the boundary integral equation discretization. Under the assumption of low passing speed, the effect of free surface elevation is neglected in the numerical calculation, and infinite image method is used to deal with the finite water depth effect. The time stepping method is used to solve the velocity potential at each time step. Detailed convergence study with respect to time step, panel size and Green function is undertaken. The present results of hydrodynamic forces are compared with those obtained by slender-body theory to show the validity of the proposed numerical method. Calculations are conducted for different water depths and lateral distances between ships, and the detail results are presented to demonstrate the effects of these factors.     

Computation of the viscous hydrodynamic forces on a KVLCC2 model moving obliquely in shallow water

The viscous hydrodynamic force and moment on ships moving obliquely in shallow water axe important for ship navigation safety. In the paper, the viscous flow field around a KVLCC2 model moving obliquely in shallow water is simulated and the hydrodynamic drag, lateral force and yaw moment acting on the hull are obtained by a general purpose computational fluid dynamics (CFD) package FLUENT with shear-stress transport (SST) k-w turbulence model. The numerical computation is performed at different drift angels and water depths. The numerical results are compared with experimental results, and a good agreement is demonstrated.     

船舶靠泊操纵模拟过程中的计算方法研究

在船舶靠泊操纵仿真中,由于船舶不能视为质点运动,因此船岸距离的计算不能简单地归结为点线距离,而应该用多边形间距方法进行计算。本文对这一问题进行了专门研究,找到一种将计算与判别合二为一的数值计算方法。该方法能避免坐标的组合判别,减少出错可能,而且简单易用。经仿真实践使用,能正确有效地完成多边形间距离的计算,具有一定的实用价值。     

预应力砼桩式防撞设施性能试验研究

通过4根预应力砼靠船桩的试验,并结合有限元分析计算,研究了张拉控制应力、砼强度、配筋率等对靠船桩的裂缝形态、裂缝的闭合性能、桩的极限承载能力、总的变形性能和吸能效果的影响。在试验和理论分析计算的基础上,对预应力砼靠船桩的张拉控制应力、砼强度、截面配筋等提出了设计建议。     

公交停靠站停靠时间特征分析

公交停靠站停靠时间的研究有着重要的实用价值。在分析影响公交停靠时间的各个因素后,根据实地调查数据统计分析各个影响因素对停靠时间的影响特征,并在此基础上提出减少公交停靠时间延误的对策。     

基于轨迹特征的船舶停留行为识别与分类

为准确评估大规模轨迹数据中的船舶停留活动，构建了两阶段船舶轨迹停留点提取策略，提出了特征驱动的船舶停留行为识别与自动分类方法；以距离、时间和轨迹点数量为约束条件构建了规则模型，检测了原始轨迹中的停留候选轨迹，引入孤立森林算法检测和去除异常离群点，提取了高聚集度的船舶停留轨迹集合；基于船舶靠泊和锚泊的时空特征，定义了轨迹点重复率、相邻点平均距离和最远点对距离3个指标，构建了新的轨迹相似性度量模型，量化了船舶停留轨迹点的分布特征和聚合程度，并利用K近邻算法完成了船舶锚泊行为与靠泊行为的自动分类；采用提出的方法处理了3个不同水域的船舶轨迹数据，准确获取了船舶停留行为的分类结果，并验证了船舶锚泊与靠泊在轨迹时空特征上的差异性，以人工标注结果为参考依据评估了船舶停留行为识别与分类的准确性。研究结果表明:船舶靠泊的轨迹点重复率在80%以上，最远点对距离和相邻点平均距离分别为6~11和1~2 m，船舶锚泊的轨迹点重复率在10%以下，最远点对距离和相邻点平均距离分别为150~250和8~10 m，说明轨迹点重复率、相邻点平均距离和最远点对距离这3个时空特征对船舶靠泊和锚泊具有显著的区分能力；提出的方法对船舶停留识别分类的正确率在98%以上，充分证明了其有效性；采用提出的方法可更新已有码头和锚地的空间位置，自动识别规则水域外的船舶异常停留和规则水域内的超长时间船舶异常停留，掌握在港船舶停留分布情况，识别不同季节、不同时段的热点码头和锚地，从而辅助优化港口规划布局和交通组织。      

基于浅水海浪数值模型的近岸海浪仿真

针对航海模拟器中视景仿真的要求,对海浪进行实时仿真.在分析近岸水波模拟中几何合成法和物理方法的基础上,提出一种利用浅水海浪SWAN数值模型的近岸海浪仿真方法.该方法基于Gerstner海浪波形,通过对需要模拟水域进行水深数据采集,应用SWAN对网格化水深数据进行相应的计算,得到近岸海域的波高、相位以及频率数据.通过采样得到Gerstner波形所需参数进行合成.基于GPU实现了LOD海面的几何绘制和光学效果.实验表明,该方法在满足近岸水波数值特性的同时,绘制方法简单且速度快,能够满足航海模拟器近岸航行训练的需求.     

罗泾港码头的长江散货船靠离泊操纵研究

针对罗泾港码头及其水域的特殊环境,文章阐述了船舶靠离泊操纵的基本原理及规律,并提出了长江散货船在罗泾港码头开展靠离泊操纵的方法、技术和注意事项。     

实用型三本船模拟器在内河船员教育中的应用与探讨

文中介绍内河船员教育中的模拟器有关功能,利用模拟器进行船舶训练的方案制作、训练实施和注意事项,着重介绍利用航海模拟器进行船舶靠泊训练的应用与教学探讨。通过模拟器实操训练,能提高学员动手能力、掌握操作技能,更好地保证船舶航行安全。     

欠驱动船舶非线性滑模靠泊控制器

为了准确控制典型靠泊操纵,分析了带有加速度非完整约束的欠驱动水面船舶的自动靠泊问题,设计了动态输出反馈控制器。利用递归分解迭代设计方法,在扩展状态空间定义了非线性滑模,将控制系统的轨迹设计与跟踪问题转化为标量零阶系统的镇定控制问题,结合增量反馈技术,无需对不确定模型参数以及风、流干扰进行估计,完成典型靠泊操纵的自动控制。仿真结果表明:控制器对干扰变化不敏感,具有强的鲁棒性,且船舶平面运动轨迹设计过程简单,可以仅通过一个参数进行轨迹调节。     

Sensitivity Analysis of Wave Slamming Load with Respect to Wind Load for Semi-Submersible Platform Design

A design of offshore floating structure is mainly based on the extreme response analysis due to the forces experienced. The extreme response can induce the negative air gap response and potential impact to the deck bottom of floating structure. It is important to predict the slamming load in order to check the strength of local structures which withstand the wave slamming. In recent years, studies of the effects of wind load on air gap response and slamming load are ignored. When the platform suffers the extreme wave, the wind is also harsh.Moreover, the wind load can affect the motion response of the platform. The wind load cannot be simulated easily by model test in towing tank whereas it can be simulated accurately in wind tunnel test. Though the model test results are not accurate enough for air gap and slamming load evaluation due to the loss of wind effect, they can be used as a good basis for tuning the radiation damping and viscous drag in numerical simulation. This paper aims at presenting the sensitivity analysis results of wave slamming load with respect to the wind load for the design of semi-submersible platform. As an example of semi-submersible drilling platform design, the wind tunnel test has been carried out, and the sea-keeping model test is also performed in towing tank, while the wind load effect is ignored. According to the model test results, a numerical model is tuned and validated by ANSYS AQWA. Sensitivity analysis studies of the relative velocity between water particle and platform surface and the wave slamming load with respect to the wind load are performed in time domain by the tuned numerical model.Five simulation cases about the presented platform are simulated based on the results of wind tunnel tests and sea-keeping tests. The sensitivity analysis results are valuable for the floating platform design.     

The settlement characteristic of underground urban complex in Shanghai

The effects of excavation unloading, construction reloading and underground water on basal heave of excavation projects were presented and analyzed based on the measurement results of an underground urban complex which was located in Shanghai. The effects on water pressure and building settlements were analyzed as well. The numerical analyses by finite element method (FEM) were conducted. It showed that the soil under the excavation base continued to heave during the following certain construction stage. It also found that the bearing capacity of uplift piles which supported the buildings affected the structure quality significantly. The conclusions can be applied in future projects. Foundation item: the National Natural Science Foundation of China (No. 50679041)     

长沙某地铁工程对白沙井影响的研究

自沙井是长沙市轨道交通1号线建设过程中必须重点保护的国家一级文物,评价地铁建设对白沙井水文地质环境条件的影响,将在一定程度上决定1号线的线路走向与施工方法．综合多种资料,初步分析了白沙井水源补给的边界、补给介质与泉井类型,并结合长沙市轨道交通1号线的规划设计,重点分析了城南路站、侯家塘站、南湖路站及其区间对白沙井水源、水质的影响;明确指出因侯家塘站切割白沙井补给含水层,应进行专门性评价;并根据既有的地下水示踪试验成果及其他相关的钻探、物探及地下水位测试成果,采用加拿大Waterloo大学的三维地下水流动数值模拟软件-VisualModflow模拟白沙井处天然径流场,进一步分析了拟建侯家塘站对白沙井影响,并提出了设计与施工中最大程度保护白沙井的方案和建议．     

水翼船机动操作特征探讨

水翼船以其独特的翼航技术,在安全、高速、舒适和增效方面优势明显。本文探讨了水翼船的掉头、靠离泊操作特征,旨在提高水翼船实际操作安全性。     

Responses of the strata and supporting system to dewatering in deep excavations

In order to prevent the inrushing caused by deep excavations, dewatering measure has to be adopted to decrease the confined water level. In this study, the responses of the strata and supporting system to dewatering in deep excavations are investigated through numerical simulations and case studies. Coupled fluid-mechanical analyses are performed by the use of the numerical software, FLAC3D. The responses of the ground settlement, base heave and interior columns to the excavation and dewatering are analyzed. Numerical results indicate that the dewatering measure can effectively reduce the uplift of the subsurface soil in the excavation, and decrease the vertical displacement of the supporting system. In addition, field data of two case histories show the similar responses and confirm the validation of the numerical results. Based on the analyses, dewatering in the confined aquifer is recommended as a construction method for controlling the vertical displacement of the strata and supporting system in deep excavations.     

舾装船舶出坞及靠离泊操纵安全研究

根据船坞的地理位置、气象和水文情况,确定计算拖轮配置及舶船出坞方案,分析了船舶出坞时应注意的有关问题。本文根据某工程舾装码头最大靠泊船型为3万吨级化学品船（兼顾停靠1万吨级化学品船）,进而确定其舾装船舶出坞方案及靠离泊操纵过程中安全保障措施。     

Numerical study on bank effects for a ship sailing in shallow channel

A numerical study on bank effects in shallow channels is carried out by using a first-order Rankine source panel method. A container ship sailing along a vertical bank and a sloping bank at different forward speeds, different water depths and different distances between the bank and the ship hull is taken as example. The sway force and yaw moment acting on the hull are calculated and the influences of the speed, water depth and distance between the bank and ship hull on the hydrodynamic force and moment are analyzed. This study can provide insight into the bank effects, as well as to give guidance on ship manoeuvring and control in restricted waterways, which is helpful to the navigation safety.