Monitoring result analyses of high slope of five-step ship lock in the Three Gorges Project

The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation in June 2003. The side slopes of the ship lock are characterized by great height（170 m）, steepness （70 m in height of upright slope）, and great length （over 7000 m in total length）. Inassociation with the ship lock, the surrounding rocks in slope have a high potential to deform, withwhich the magnitude of deformation is restricted. Monitoring results show that the deformation of thefive-step ship lock high slopes of the TGP primarily occurred in excavation period, and deformationtended to be stable and convergent during operation period, suggesting the allowable ranges of deformation.At present, the slopes and lock chambers are stable, and the ship lock works well under normaloperation condition, enabling the social and economic benefits of the TGP. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

Numerical Study of Viscous Wave-Making Resistance of Ship Navigation in Still Water

The prediction of a ship＇s resistance especially the viscous wave-making resistance is an important issue in CFD applications. In this paper, the resistances of six ships from hull 1 to hull 6 with different hull forms advancing in still water are numerically studied using the solver naoe-FOAM-SJTU, which was developed based on the open source code package OpenFOAM. Different components of the resistances are computed and compared while considering two speed conditions （12 kn and 16 kn）. The resistance of hull 3 is the smallest while that of hull 5 is the largest at the same speed. The results show hull 3 is a good reference for the design of similar ships, which can provide some valuable guidelines for hull form optimization.

Formal safety assessment and application of the navigation simulators for preventing human error in ship operations

The International Maritime Organization (IMO) has encouraged its member countries to introduce Formal Safety Assessment (FSA) for ship operations since the end of the last century. FSA can be used through certain formal assessing steps to generate effective recommendations and cautions to control marine risks and improve the safety of ships. On the basis of the brief introduction of FSA, this paper describes the ideas of applying FSA to the prevention of human error in ship operations. It especially discusses the investigation and analysis of the information and data using navigation simulators and puts forward some suggestions for the introduction and development of the FSA research work for safer ship operations.

Structure Analysis of Locking Mechanism of Gear-Rack Typed Ship-Lift

Contact nonlinear theory was researched. Contact problem was transformed into optimization problem containing Lagrange multiplier, and unsymmetrical stiffness matrix was transformed into symmetrical stiffness matrix. A finite element analysis （FEA） model defining more than 300 contact pairs for long nut-short screw locking mechanism of a large-scale vertical gear-rack typed ship-lift was built. Using augmented Lagrange method and symmetry algorithm of contact element stiffness, the FEA model was analyzed, and the contact stress of contact interfaces and the von Mises stress of key parts were obtained. The results show that the design of the locking mechanism meets the requirement of engineering, and this method is effective for solving large stole nonlinear contact pairs.

Numerical Prediction of Hydrodynamic Forces on A Ship Passing Through A Lock

While passing through a lock, a ship usually undergoes a steady forward motion at low speed. Owing to the size restriction of lock chamber, the shallow water and bank effects on the hydrodynamic forces acting on the ship may be remarkable, which may have an adverse effect on navigation safety. However, the complicated hydrodynamics is not yet fully understood. This paper focuses on the hydrodynamic forces acting on a ship passing through a lock. The unsteady viscous flow and hydrodynamic forces are calculated by applying an unsteady RANS code with a RNG k-e turbulence model. User-defined function （UDF） is compiled to define the ship motion. Meanwhile, the grid regeneration is dealt with by using the dynamic mesh method and sliding interface technique. Numerical study is carried out for a bulk carrier ship passing through the Pierre Vandamme Lock in Zeebrugge at the model scale. The proposed method is validated by comparing the numerical results with the data of captive model tests. By analyzing the numerical results obtained at different speeds, water depths and eccentricities, the influences of speed, water depth and eccentricity on the hydrodynamic forces are illustrated. The numerical method proposed in this paper can qualitatively predict the ship-lock hydrodynamic interaction. It can provide certain guidance on the manoeuvring and control of ships passing through a lock.

On the treatment of thermal cracks in lining concrete of water conveyance system of Three Gorges Project permanent ship locks

A comprehensive investigation was performed for repairing the different types of cracks appearing on the surface or inside the concrete lining at various depths.The mate- rial properties used in grouting and two methods for crack repair were discussed in details, and consequently reliable repair measures were proposed and implemented.It is a better choice to adopt the hole-drilling method for the relatively regular crack.The grouting pres- sure should not be too high and it is generally between 0.4～0.6 MPa.For the second time grouting,the pressure maybe increased to 0.8 MPa.Other method is the pasting nozzles method which is more suitable for irregular cracks such as cracks with intensive density and crossing cracks.Its grouting pressure is generally between 0.6～1.0 MPa.The in-situ tests in Three Gorges Project demonstrate favorably the feasibility and applicability of the proposed methods for crack repair within the lining concrete.

Elucidation of Latent Risk of Navigation Using an Actual Ship Behavior Analysis

In recent years, maritime transportation has played an important role in global economy development. As a result, ship traffic has become more congested. Moreover, ship navigation is susceptible to weather and environmental conditions, and in some cases, it may become dangerous. Therefore, vessels are subjected to high-risk navigation conditions. To understand the latent risk of ship navigation, this study focused on the actual ship behavior. Thus, an analysis of ship behavior was carded out using historical ship navigation based on automatic identification system data. Consequently, a dynamic analysis of the speed and encounter situation was performed. One of the main results of this work was the understanding of the latent risk involved in ships navigating the Seto Inland Sea, which is one of the most congested routes in Japan. Moreover, the risk areas were obtained, and visualized using a geographical information system. The obtained results can be applied to ensure safe navigation and the development of a safe and efficient navigation model.

Simulation Analysis on Navigation Indexes of Wanzhou Yangtze River Highway Bridge after the Anti-Collision Device Construction by Ship Model Test

After the anti-collision facility construction of Wanzhou Yangtze River Highway Bridge, the conditions of navigation in bridge area are complex. In order to study the navigation conditions of the reach and layout optimization measures, ensuring the safety of the ship navigation test has been carried out on the ship model navigation in the bridge area. According to the requirements of the maximum safety limit of the ship model test, the paper puts forward the best route, the control method and the difficulty of navigation through the analysis of the test results, and finally gives the recommendations and suggestions.

基于人工势能场的破冰船护航下船舶航行风险场建模

针对破冰船护航下船舶碰撞与冰困事故风险评估问题,本文根据破冰船与跟驰船之间、跟驰船与海冰之间的相互关系,并基于人工势能场理论提出破冰船护航下船舶航行风险场的概念和模型,其中包括破冰船风险场和海冰风险场。破冰船风险场量化破冰船与跟驰船之间的碰撞风险水平,海冰风险场量化跟驰船与海冰之间的冰困风险水平。根据该模型提出破冰船与跟驰船之间安全跟驰距离的计算方法。最后基于Tian You轮2018年北极编队航行数据,应用破冰船护航下船舶航行风险场模型开展仿真实验,仿真结果验证了航行风险场模型的有效性,证明了本文建模方法能够为破冰船护航下船舶安全跟驰研究提供理论方法支撑。

抚河疏山水利枢纽船闸通航水流条件研究

为满足水运需求,解决船闸引航道口门区受河段地形和涉河建筑物影响而导致的通航条件困难等问题,保障船舶安全通行,以抚河疏山水利枢纽船闸工程为例,采用数值模拟方法,对枢纽船闸上游引航道口门区通航条件进行计算分析,针对不良流态问题提出优化方案措施,并对方案前后枢纽通航条件进行对比分析。研究表明,调整船闸平面布置等措施对改善设计阶段的枢纽船闸上引航道口门区通航条件是有效的。研究成果可为抚河疏山水利枢纽船闸工程通航及其他类似河段工程提供技术支持。

沅水桃源枢纽左岸船闸桥区船模通航条件试验研究

沅江大桥通航环境十分复杂,原大桥通航孔布置不合理,严重制约了桃源枢纽二线船闸扩建工程建设。针对桥区通航条件差的问题,对其左岸桥梁通航孔布置方案进行船模试验研究,采用定床河工模型和小尺度船模试验相结合,并从船模试验的舵角、漂角和航速等航行参数进行综合分析,结果表明:在相同通航总净宽的情况下,双孔双向要优于双孔单向;桥梁通航孔右移可降低一线船闸船舶下行过桥难度,但会增加二线船闸船舶上行过桥的难度。建议左岸新建桥梁通航孔净宽应不小于220 m,桥位相比于现状桥梁右移约75 m,采用双孔双向,两线船闸分槽航行的方式。

无人机立体视觉识别船舶航行风险仿真

由于船舶交通受碰撞、搁浅、走锚等随机干扰因素的影响,导致对船舶航行目标的跟踪与风险预警具有较大难度。为增强海上航行的安全性,提出一种基于无人机立体视觉的船舶航行风险识别方法。引入双目视觉立体技术,获得目标船舶在航行过程中的图像数据。利用卡尔曼预测器优化连续性自适应均值漂移算法,跟踪目标船舶,通过高斯混合模型识别船舶航行风险。实验结果表明,研究方法对不同海域的船舶跟踪曲线与船舶实际航行曲线具有较高拟合度,且上述方法的船舶航行风险识别正确率高于90%,且误报率低于0.2%,说明提出方法的应用可靠性较高。

多种通航建筑物组合布置的通过时间研究

山区航道高水头通航建筑物多采用船闸、升船机、隧洞和中间渠道组合布置的形式。多种通航建筑物组合布置时,各通航建筑物的通过能力相互制约和影响,计算较为复杂。结合工程实际,在通过能力计算中,分析了通过各建筑物时间的匹配性及其对通航效率的影响,指出在组合布置通航建筑物时,应以船闸或升船机1次运行时间为基础,复核计算通航隧洞、辅助闸门等其他通航建筑物的1次运行时间是否小于基础时间,当大于基础时间时,应合理调整组合形式、布置形式和建设规模,成果可为类似工程提供参考。

两坝间河道高含沙水流驱动的下游船闸阀门井水位异常特征分析

葛洲坝船闸充水阀门井与输水廊道进水口水体相连,1993年洪季期间曾发生过阀门井水位异常升高,影响船闸设备设施安全等问题。为分析葛洲坝一号船闸充水阀门井水位异常升高的根本原因,基于Mike三维水沙数值模型,模拟分析了不同流量和含沙量级别下的河道水流和含沙量垂向分布结构特征,进而计算阀门井水位异常升高值与河道水流和含沙量的关系,反演1993年洪季葛洲坝一号船闸两个阀门井出现的水位异常现象。研究结果表明,葛洲坝一号船闸阀门井水位异常超过阈值0.5 m的流量和含沙量条件分别约为(30 000 m^(3)/s, 2.85 kg/m^(3)),(40 000 m^(3)/s, 1.42 kg/m^(3)),(50 000 m^(3)/s, 1.23 kg/m^(3))。受三峡水库及上游梯级水库蓄水拦沙、退耕还林政策等因素的影响,未来葛洲坝船闸出现高含沙水流导致阀门井水位异常升高>0.5 m的可能性极小,但在三峡水库排沙泄洪期间仍应引起重视。研究成果可为葛洲坝一号船闸安全营运和科学管理提供参考依据。

基于虚拟现实技术的船舶航行实景三维模型设计

为提升船舶驾驶人员及船员的船舶整体认知以及海况应对能力,确保船舶航行以及作业安全,设计基于虚拟现实技术的船舶航行实景三维模型。按船舶航行需遵循的物理定律以及原理,建立船舶航行运动姿态数学模型,并通过3Dmax构建船舶航行环境实体以及地形模型,利用PM海浪谱法构建海表面三维模型,而后通过Unity3D虚拟现实仿真软件驱动调整构建的三维模型,并对所构船舶三维模型采用改进混合包围盒法实施碰撞检测,把地形以及海浪等实际数据信息融入到导入的模型之中,仿真模拟船舶航行实景,实现人机交互。实验结果表明,基于虚拟现实技术实现的船舶航行实景三维模型,可较为真实模拟船舶航行实景,为确保船舶航行以及作业安全提供可靠参考与保障。

完全预约模式下船闸通航调度方法分析

针对现有部分船闸通航效率不高,通航拥堵严重等问题,以完全预约模式下船闸通航调度方法为研究对象,考虑闸室有效面积利用率最大和平均预约延误时间最小,在BL算法的基础上,建立了基于人工蜂群算法的船闸通航调度模型。选取三峡双线五级船闸的过闸船舶数据,通过与原始人工编排、BL算法编排结果进行比较,发现人工蜂群算法性能稳定,能显著提高闸室面积利用率,且平均利用率大于80%。此外,在平均预约延误时间方面有明显的降低效果。

根据DS理论的船舶风险因素评估分析

针对船舶航行风险评估中存在许多不确定影响因素的问题,提出了在模糊风险评估证据理论基础上建立的风险评估方法。在证据集理论空间中,每一事件均可确认为模糊集合子集且融入了模糊概率理论,从而更全面地描述行业学者的专业经验或证据诠释,由此得出了模糊证据理论质量函数的描述法。最后应用其船舶安全系统,提出了船舶风险因素识别和风险评估详细程序。计算结果证明,此方法可有效避免决策失误,且简单、易行,有较强的推广和应用价值。

内河水运基础设施及船舶技术发展现状与展望

我国交通运输事业已步入全面建设交通强国的新发展阶段,内河水运在综合交通运输体系中的比较优势尚未得到充分发挥,而“双循环”新发展格局及“双碳”战略的实施将要求内河水运及其核心要素的船舶技术必须实现创新发展。该文通过梳理提炼国内外内河水运以及船舶发展的现状与相关政策演变,分析创新技术研究进展与典型案例,对内河水运基础设施及船舶技术发展趋势进行展望:未来内河水运基础设施与数字、信息和网络技术深度融合,岸基控制中心作为关键性设施和船舶能源供给设施网联化;船舶则向着船型标准化、谱系化、智能化、少人化、能源绿色化及多元化、电力推进主流化等方向演进;船舶编队航行成为创新运输模式。文中所探索的内河水运基础设施及船舶技术的变革方向,可为建设新一代内河水运体系和研发先进船型提供参考。

无人作业船自动导航控制系统的优化

为了提高原有导航系统中低成本传感器的数据检测精度和船体航迹跟踪的控制效果,引入数据融合算法并提出了一种新型的航迹跟踪算法.导航系统首先对船体进行多次坐标变换,通过两次卡尔曼滤波器融合出更精准的船体航向角、坐标和速度;其次提出了一种基于消除航迹速度偏差和航向角偏差的控制算法,将传统的PID控制器设计成由PI控制器和微分控制器组成的串级控制系统,作为内环的微分量正好由现有的加速度计和陀螺仪检测变送,省去了对微分参数的调节,对检测精度不高的系统也可以有较好的控制效果;最后解算出船体两个明轮各自需要的出力情况,以提高航迹跟踪效果.在试验平台上控制无人作业船进行多次巡航试验,通过上位机实时监测船体的状态数据和运行轨迹,并对整体优化后的航迹跟踪效果进行了分析.结果表明:经卡尔曼滤波器融合后的航向角、定位和速度,数据方差更小,更接近于理想值;对于控制算法,系统的超调量不超过3%,响应速度足够快,且稳态误差接近0;航迹跟踪的直线段成功率由优化前的80%提升到了95%,拐弯段的成功率由优化前的60%提升到了90%,直线段的最大偏航平均距离由优化前的0.83 m降到了0.12 m,拐弯段的最大偏航平均距离由优化前的1.25 m降到了0.22 m;拐弯后平均需要0.95 m长的调整距离就可以进入直行状态,直线段和拐弯段的跟踪效果明显得到了改善.

船闸深孔反弧门实时在线监测技术应用研究

针对船闸输水系统工作反弧门长期在深孔动水条件下频繁启闭,给船闸安全运行造成安全隐患,提出一种深孔反弧门实时在线监测技术方案。为掌握深孔反弧门运行情况,将已密封好的应变及倾角等传感器布置在闸门上,再利用钢丝网架胶管将采集信号输送至在线监测系统。监测系统实时进行反弧门在线监测与数据显示,并实时分析结构应力、运行姿态及启闭力,根据分析结果,给出不同等级报警信息及相应的处置建议,提示运行操作人员对反弧门采取对应措施。对广西大藤峡水利枢纽船闸反弧门实施实时在线监测,测试数据表明实施的反弧门实时在线监测系统是可靠稳定的,证明将实时在线监测技术应用于深孔且动水频繁启闭的闸门是可行的。