浅谈黄河堤防工程维修养护中的施工管理

黄河堤防工程由于长期受维修经费短缺、重建轻管思想影响,工程维修养护得不到重视,大多数出现了年久失修、带病运行情况。影响了工程完整和工程面貌,降低了工程抗洪强度。水管体制改革后,这一问题得到根本解决,通过对堤防工程高标准维修养护,增强了工程的抗洪强度,改善了工程面貌,提高了工程管理水平。     

航道工程竣工验收主要内容有哪些？

航道工程竣工验收主要内容包括：检查工程的批准、核准、备案等文件是否齐全；检查工程是否按批准的规模、标准、内容全部建成；检查国家和行业强制性标准的执行情况；检查工程招投标以及合同履约情况；检查工程交工验收情况；检查工程实体质量以及工程效果；检查航运枢纽工程的阶段验收情况；检查工程试运行情况；检查专项验收情况；检查工程竣工决算报告的审计情况；对存在的问题和尾留工程提出处理意见等。     

《航道工程地质勘察规范》的修改建议

《航道工程地质勘察规范》（JTS133—3—2010）是按工程类别对各勘察阶段的勘察工作进行规定的,不利于从宏观上把握工程地质条件,建议按照勘察阶段,分别对各类工程进行规定,并对各勘察阶段勘察报告的主要内容进行规定;规范缺少堤防工程地质勘察的规定,建议增加堤防工程地质勘察的规定,这样有利于统筹考虑勘察方案;规范未将渠化工程中航道工程很好地融入,建议将渠化工程融入进来,形成一个完整的航道工程体系勘察规范,便于使用。     

水电建设项目工程变更管理及控制

工程变更贯穿工程项目实施全过程,水电建设项目受自然条件和客观因素的影响大,工程变更不可避免要发生,文章在对水电建设项目工程特点、工程变更类型分析的基础上,就如何控制工程变更的发生进行了分析,可供相关工程借鉴参考。     

上海港机CIMS工程概况与现状

介绍了上海港机CIMS工程概况,计算机信息处理的工作现状,CIMS工程的功能目标、集成目标,CIMS工程的功能模型以及工程实施方案与工程实施现状。     

工程总承包档案工作的重要性及我单位的档案工作实践

我公司原是一家部属具有工程咨询、设计、监理甲级资质的综合型设计院，以勘察设计为主要业务。2007年，我公司进入中石油系统，从传统的设计单位转为以工程总承包为核心业务的现代化工程公司。在工程总承包项目管理中，档案管理是一项重要内容，要做好工程总承包项目，就必须做好工程总承包档案的管理。本文以本公司工程总承包档案工作的实践为例，对石化设计企业工程总承包档案管理进行一些探讨。     

公路工程BT项目投标文件的编制技巧

文中依托安徽池州殷查公路BT工程招投标,介绍了我国公路工程BT工程投标文件的编制方法,论述了BT工程和非BT工程投标在文件编制中的区别以及公路工程BT项目组成方式,指出编制BT工程投标文件的重点,可供能给工程建设类似工程提供一些借鉴。     

做好隐蔽工程是保证工程质量整体优良的基础

阐述隐蔽工程的重要性,工程隐蔽的主要形式,工程隐蔽容易出现问题的原因,以及搞好隐蔽工程的一些做法。     

优化土石方调配模型在某工程中的应用

如何根据实际情况得出经济、有效的最优调配方案,是土石方工程的一个重要课题.舟山某工程主要包含开山工程、围堤工程及陆域形成工程,其中程石料用量全部取自开山工程.依据线性规划理论,提出适用于该工程的土石方调配计算的基本思路,建立土石方调配优化模型并最终得出优化结果,最后分析各重要参数对调配结果的影响,以期对今后土石方调配工程有一定的借鉴作用.     

我国水运工程测量技术现状及展望

依据《水运工程测量规范》以及现实水运工程测量服务内容首次对水运工程测量进行了详细分类,该分类涵盖了水运工程测量所能提供服务的全部内容,并根据此分类对水运工程测量现阶段的理论发展和应用技术手段状况进行了详细分析,同其他领域中的测绘水平进行了比较分析,综合评价了水运工程测量在现代测绘领域中发展的技术水平和地位。根据目前水运工程测量的实际服务能力指出了水运工程测量行业存在的问题,并就测绘理论和技术手段的发展,针对水运工程测量的特点和今后水运工程发展的实际要求,对水运工程测量的发展方向进行了预测。     

Vibration-assisted decommissioning of a slip joint: Application to an offshore wind turbine

An alternative option to the traditional grouted joint for wind turbines is a direct steel-to-steel connection, also known as slip joint. In a recently published work, a proof of concept of a vibration-assisted installation and decommissioning technique of a slip joint was illustrated. Leveraging on the obtained results, the current study shows for the first time a decommissioning campaign carried out using a vibration-assisted technique applied on a prototype hydraulic wind turbine tower located in the North Sea, and connected to the monopile through a slip joint. The key aspect of the dismounting procedure is a priori knowledge of the resonance frequency clusters corresponding to the slip joint’s cross-sectional modes. Therefore, field hammer tests and experimental modal analysis were carried out inside the wind turbine tower. The identified frequencies and mode shapes were then compared with numerical ones estimated by a finite element model of the investigated structure. The comparison showed that a set of frequency clusters can be directly selected from a detailed numerical model. The preparatory work of the slip joint decommissioning was then executed by installing electric shaker devices, based on the dynamic identification results, and hydraulic jacks mounted inside the wind turbine tower. A first decommissioning trial was carried out in May 2019, while the final decommissioning was performed in August 2019. After analysing the measurements of the hydraulic pressures, displacements and excitation frequencies during the decommissioning campaigns, the results showed that it is possible to disconnect the slip joint if, in combination to a vertical static force, one of the identified cross-sectional mode shapes is excited. The vibration-assisted decommissioning proved to be a successful technique to dismount the connection in a controlled and straightforward manner.     

船用柴油机故障在线智能仿真诊断技术的应用研究

本文提出了一种船用柴油机性能故障在线自动诊断的新方法,把仿真以及神经网络技术直接应用于柴油机故障在线诊断系统,建立船用柴油机症状与故障样本集,作为神经网络故障诊断的专家知识库,以和柴油机故障在线诊断。尤其是对网络容错能力进行评估分析,并确定较有代表性的径向基函数ＲＢＦ网络分布常数Ｓｃ,从而提高故障诊断的及时性和准确率,减少误诊。     

影响船舶弃船时机决策的各环境因素分析

当船舶发生海难事故后,船舶弃船时机的正确决策关系到船舶安全尤其是海上人命安全,本文分析了影响该决策行为的各种环境因素,对弃船时机的正确选择做一个初步分析,为进一步研究奠定一些基础。     

Optimal reefer slot conversion for container freight transportation

Given a fleet of container ships of varying capacity, a cost-efficient approach for improving fleet utilization and reducing the number of delayed containers is to optimize the sequence of container ships in a given string, a problem which belongs to the large ship-deployment class. A string sequence with ‘uniformly’ distributed ship capacity is more likely to accommodate a random container shipment demand. The number of one’s total ship slots acts as a gauge of the capacity of the container ships. Meanwhile, there are two types of ship slots: dry slots and reefer slots. A dry slot only accommodates a dry container, while a reefer slot can accommodate either a dry or a reefer container. The numbers of dry and reefer slots for ships in a string are different. Therefore, in this study, we propose a model that considers both dry and reefer slots and use it to elucidate the optimal ship-deployment sequence. The objective is to minimize the delay of dry and reefer containers when the demand is uncertain. Furthermore, based on the optimal sequence deduced, the study also investigates the need to convert some dry slots to reefer slots for the container ships.     

Study on a new method for installing a monopile and a fully integrated offshore wind turbine structure

This paper presents a preliminary technical feasibility study on a new methodology proposed for installing a monopile-based bottom supported offshore wind turbine structure. The concept is developed to address the problem of “waiting for a suitable weather window” which is commonly faced by the existing installation methods that uses a typical jack-up platform. In the methodology, a floating vessel along with a floatable subsea structure fitted with a hull on the top, hereafter named SSIP (subsea structure for installing a pile), is proposed first to install a monopile. Then the same structure is used to carry an FIUS (fully integrated upper structure) of an offshore wind turbine, which is characterized by a telescopic tower, and install it over the monopile by using an FOP (float-over-pulling) arrangement. Here, the installation methodologies are first briefly described along with the critical load cases associated with them. These load cases are then numerically studied for a significant wave height (H_S) of 2.5 m, and the results are summarized. For installing a fully integrated offshore wind turbine upper structure on a monopile foundation by the FOP method, two installation schemes are presented, and their dynamic characteristics are compared. It is shown that the proposed methodologies have potential to provide installation solutions which can be environmentally more robust compared to the existing method for installing an offshore wind turbine.     

Locomotion by mechanical pectoral fins

The objectives of this study were the development of a new device for maneuvering an underwater vehicle using the mechanism of a fish swimming, an experimental and theoretical analysis of the hydrodynamic characteristics of the device, and its application to maneuvering a fish robot. Observations and experimental analysis of the pectoral fins of a black bass (Micropterus salmoides) revealed that the locomotion of the fish, such as swimming forward at low speed, swimming backward, and turning in a horizontal plane is generated by using a combination of a feathering motion and a lead-lag motion of the pectoral fins. A mechanical pectoral fin making a feathering motion and a lead-lag motion generates a thrust force in a range of phase differences between both motions. The unsteady vortex lattice method, including the effect of viscosity, can express fairly well the unsteady forces acting on the mechanical pectoral fin in the range of phase differences where it exerts the thrust force. The fish robot, consisting of a model fish body and a pair of mechanical pectoral fins, can not only swim forward and turn in almost the same position, but can also swim in a lateral direction without changing the yaw angle. Translation of an article that appeared in the Journal of The Society of Naval Architects of Japan, vol. 182 (1997): The original article won the SNAJ prize, which is awarded annually to the best papers selected from the SNAJ Journal, JMST, or other quality journals in the field of naval architecture and ocean engineering.     

船舶在狭水道中运用GPS、ARPA、ECDIS定位技术研究

船舶在狭水道或进出港航道航行时,为确保船舶航行在预定的航迹线上,传统的定位与导航方法大多是利用助航标志。本文基于GPS、船用雷达(ARPA)和电子海图(ECDIS)等航海仪器与设备功能特点,就船舶运用GPS、船用雷达和电子海图以确定船舶在狭水道航行的航迹线方法作了研究,并就方法的运用提出了相应的注意事项。     

医院船医疗流程与总布置设计探讨

医院船是一种新船型,用于收容和治疗伤病员的专用卫生船只,医疗流程是医院船总布置设计的主要因素。因此在设计中必须根据船的使命,最终确定整个船的总布置,本文推荐了一艘医院船的总布置供参考。     

A risk assessment model with systematical uncertainty treatment for container shipping operations

ABSTRACT

The substantial adverse effects of risk factors on container shipping and logistics promoted a deep integration of risk analysis into the decision-making process. This paper aims to develop a well-grounded quantitative model to operational risk in a container shipping context. Considering uncertainty as a primary component of the risk concept, methods were employed in an inter-complementary manner to enable not only a sense of foreseeability but also a deeper look into the weaknesses of the knowledge base. The intersubjectivity of the input extraction process was supported by the Evidential Reasoning (ER) algorithm. Risks are then assessed based on a Fuzzy Rules Bayesian Network (FRBN) model with a 2-level parameter structure before meaningful interpretations can be derived through a new risk mapping approach. Besides an illustrative case study, the model was tested by sensitivity analysis and an examination of multiple validity claims.     

基于System Generator开发数字信号处理系统

在分析了传统数字信号处理开发方法不足的基础上提出采用基于SysGen的数字信号处理系统开发方法,并应用新方法设计验证了一套数字下变频系统,实验证明SysGen在数字信号处理开发方面具有明显优势。