Reliability-based optimization in structural engineering

In this paper reliability-based optimization problems in structural engineering are formulated on the basis of the classical decision theory. Several formulations are presented: Reliability-based optimal design of structural systems with component or systems reliability constraints, reliability-based optimal inspection planning and reliability-based experiment planning. It is explained how these optimization problems can be solved by application of similar techniques. The reliability estimation is limited to first order reliability methods (FORM) for both component and systems reliability evaluation. The solution strategies applying first order non-linear optimization algorithms are described in detail with special attention to sensitivity analysis and stability of the optimization process. Furthermore, several practical aspects are treated as: Development of the reliability-based optimization model, inclusion of the finite element method as the response evaluation tool and how the size of the problem can be made practicable. Finally, the important task of model evaluation and sensitivity analysis of the optimal solution is treated including a strategy for model-making with both pre and post-analysis.     

Mathematical similarities in engineering network analysis

This paper examines the proposition that structural trusses and pipe networks for water supply are closely related in a mathematical sense. It shows that in terms of representation, physical quantities, constitutive equations, analysis problem formulations and methods of analysis they both belong to the same class of nonlinear potentiated networks, the truss being a special linear case for problems of analysis. The analysis of nonlinear potentiated networks may therefore be efficiently performed by linearization of the relevant nonlinear quantities and the iterative use of well-known truss analysis methods. The commonality established between structural trusses and water supply systems has potential for exploitation in respect of other network-related problems of optimum design, reliability evaluation and design for resilience.     

Classification as a tool in rock engineering

The role of classification in rock engineering and design is discussed. It is important to distinguish between characterization, classification and empirical design method. The classification systems used today should, strictly speaking, either be described as rock mass characterization systems or empirical design methods, as long as the outcome is not organized into classes. The main requirements for a true classification system capable of solving rock-engineering problems are as follows. (1) The reliability of the classes to assess the given rock engineering problem must be estimated. (2) The classes must be exhaustive (every object belongs to a class) and mutually exclusive, (no object belongs to more than one class). (3) The principles of division (rules) governing assignment into the classes must be based on suitable indicators (ground parameters, etc.) and must include the possibility of being updated during construction using the experience gained. (4) These rules must also be so flexible that additional indicators can be incorporated. (5) The uncertainties, or the quality, of the indicators must be established so that the probability of mis-classification can be estimated. (6) The useful system should be practical and robust, and give an economic and safe design. In the author's opinion, none of the main classification systems in use today fulfills these requirements. They may, however, serve as supervised systems as a basis in the development of local systems adapted to the actual site conditions.     

提高监督水平保证工程质量

论述了我国质量监督机构应转变监督方式，运行机制的问题。从思想认识的转变，监督制度的规范化、法制化，监理队伍素质的提高几方面阐明了质量监督水平提高的途径，以便更好地保证工程质量。     

The distinctiveness of civil engineering in engineering systems thinking and in new models in engineering education

A revolution in engineering education is coming, but is civil engineering ready? Students learn differently from how they did a few generations ago and the rapid pace of technology change means that the goals of education need to change as well as the method. New engineering degree programmes are arising, and though they aspire to teach a new generation of interdisciplinary engineers, they do not seem to have been developed with civil engineers in mind. While the need for improvements in systems thinking by engineering students is acknowledged by various organisations, the uniqueness of a civil engineering response to the systems challenge is not recognised. Civil engineering education is distinct because of the large scale of the artefacts that need to be created by students, because the scope of civil engineering employment is broader, and because its need in terms of systems thinking is more than project management. The conclusions are that (1) civil engineering education needs rapid and major change, (2) a unique focus on systems is needed in civil engineering education, and (3) civil engineering education needs to follow a distinctive path from the forms that the revolution is currently taking.     

A framework for the future of urban underground engineering

A special and holistic approach is needed that captures aggregate attributes and emergent behaviors of the complex system of infrastructure systems in a region. Effective management of the impacts of future population growth, urbanization, and risks arising from continued evolution of our natural, physical and human/societal systems will require a systematic exploration and characterization of the urban subsurface, including much improved understanding and assessment of geologic risks. With recent cost escalations for underground construction projects, incentives are needed for the underground construction industry to develop and implement innovations in methods and technology, and smart integrated planning is needed to reduce costs both during construction and with life-cycle engineered design and operation of our subsurface facilities.The needed framework requires investigation of potential metrics that reflect the performance of aggregate functions of an urban environment so that we can holistically study system performance response under “normal” and “stressed” operation. Such a metric can support a cross-disciplinary exploration of urban resilience, and build knowledge as we develop and test theory and models that explore resilience of complex socio-technical systems. Econometrics with spatial and temporal granularity will help to understand the integrated functionality of our cities and to establish appropriate policies that will drive continuous improvement in the quality of urban life while providing natural, human, and physical urban environmental resilience. The underground in urban regions can become an important component of managing the increasing complexity of our physical systems, and can also make more significant contributions to improving the robustness and resilience of our future cities.     

机场工程中坐标系的转换计算

本文对我国机场工程可能存在多种坐标系现状进行了叙述,论述了这些坐标系之间相互转换的方法、数学模型、转换参数的解算过程及精度分析,说明了建立机场抵偿面坐标系的必要性,在实际算例中详细介绍了转换实现的过程,并对坐标转换的精度进行了评定;证明了机场测量控制网基于GPS精密解算获得的ITRF瞬时历元坐标,可以实现精度优于7.5cm的WGS-84坐标转换。     

摩天轮结构及其工程应用研究

为促进摩天轮的发展和应用,对摩天轮的结构体系、驱动和支承的设计以及施工技术等方面进行了研究.介绍了摩天轮的诞生过程,综述了摩天轮在各国的发展历程和应用情况,分析了摩天轮不同于一般游乐设施的技术特点.研究了摩天轮轮盘的刚性和柔性两种结构体系,论述了摩天轮的驱动系统和支承结构的设计.研究了摩天轮的单侧旋转法、两侧并进法和中心旋转法3种施工方法及其适用范围.最后提出了摩天轮未来的发展趋势以及将带来的新的研究课题.     

建筑工程深基坑支护方案的设计与施工

结合具体工程实例,介绍了两种深基坑支护方案：钢筋混凝土排桩加预应力锚索支护体系和土钉墙加预应力锚索支护体系,并具体阐述了施工方法和操作工艺,结合实际应用效果指出这两种支护方案有效降低了基坑支护成本并保证施工安全,值得推广。     

Chemical reaction engineering and activated sludge

The applicability of chemical reaction engineering principles to activated sludge systems is discussed. Based on these principles, an explanation is proposed to the similar performance of plug flow and completely mixed activated sludge systems treating municipal wastewater. The use of batch data for the design of continuous flow reactors is also explained.     

土木工程专业核心课程基础工程建设探索

基础工程课程是土木工程本科专业的核心基础课程。随着时代的发展，基础工程已应用到海洋、交通、能源和环保等领域，传统课程教学内容已无法满足社会的需求。结合国内外知名高校的先进教学理念，从教学内容、教学理念、教学方式、考核方式等四个方面，对浙江大学基础工程课程改革进行探索研究。一是将基础工程的基础理论和工程案例拓展到海洋、交通、能源和环保等新领域；二是引入情景激发式教学模式，充分调动学生的主观能动性，增强学生的课程参与感，提高学生的工程实践能力，为新时代的基础工程建设培养视野新、基础实、实践能力强的新型土木工程人才。     

现代工科院校桥梁工程课程多元化教学方式探讨

桥梁工程课程是工科院校土木工程专业道桥方向一门重要的专业课程.文章在探讨该课程的特点、教学现状、影响因素的基础上,结合现代化教学手段和丰富的网络资源,提出了扩展式、参与式、讨论式等多元化的教学方式,以激发学生学习的积极性和参与性,提高桥梁工程课程教学效果.     

Software procurement and superconcurrent engineering

An IEE Workshop held in October 1993 confirmed widely expressed concern that the present means of acquiring large complex bespoke software-based systems is unsatisfactory because the systems never fully meet the requirements of the users when they come on stream, and probably never can. Improving this situation has implications for both the technical and the commercial aspects of software procurement. The author reports how participants concluded that a useful approach to meeting the challenge would be the establishment of guidelines which would assist those responsible for the supply and procurement of software     

Resilience engineering and the built environment

The possible relations between resilience engineering and built environments are explored. Resilience engineering has been concerned with the safe and efficient functioning of large and small industrial systems. These may be described as built systems or artefacts. The resilience engineering approach argues that if the performance of systems is to be resilient, then they must be able to respond, monitor, learn and anticipate. The last ability in particular means that they must be able to consider themselves vis-à-vis their environment, i.e. be sentient and reflective systems. In practice, this means people individually or collectively can adjust what they do to match conditions, identify and overcome flaws and function glitches, recognize actual demands and make appropriate adjustments, detect when something goes wrong and intervene before the situation becomes serious. It is particularly important to understand the range of conditions about why and how the system functions in the ‘desired’ mode as well as ‘unwanted’ modes. Resilience is the capacity to sustain operations under both expected and unexpected conditions. The unexpected conditions are not only threats but also opportunities.     

An approach to teaching civil engineering systems

The approaches used in offering a required course for undergraduate students, an elective course for both undergraduate and graduate students, and a Master of Science program in civil engineering systems are described. Student attitudes about systems analysis and teaching challenges are discussed. My teaching philosophy is to integrate economic and engineering principles into an unified approach for solving civil engineering design, planning and management problems. The manner in which this philosophy is incorporated into systems courses and the MS program is illustrated.     

工程管理专业研究生运筹学教学方法探讨

运筹学是工程管理专业的一门注重组织系统管理培养的重要专业基础课,发展速度非常迅速。目前工程管理专业研究生运筹学教学过程中主要存在教学目的不明确,教学内容安排不合理,教学方法不科学,实践教学安排不足,成绩考核不科学等问题。结合多年的研究生教学和科研实践经验,文章提出运筹学课程教学改革思路,包括明确教学目的、合理确定和更新教学内容、丰富实例教学、加强运筹学软件教学,以及改进考核方式等,为推动工程管理及其他领域运筹学教学改革和培养优秀的专业技术与管理人才提供参考。     

Systems engineering in search of the elusive optimum

The current wave of enthusiasm for systems engineering is considered, and 'litmus tests' are presented to identify whether activities presented as systems engineering really justify the title. The fleeting nature of optimality is explored, showing that the need for flexible, adaptable solutions is increasing as social turbulence and tempo increase. The goal of systems engineering as seeking optimum solutions is explored together with the relationship between optimum and minimal entropy configurations. How it is possible to identify optimum conditions without the need for mathematics is illustrated. Finally, a process/life-cycle model of systems engineering is introduced which retains the flexibility and adaptability essential to deal with the dynamic markets in which we increasingly compete     

Composite steel and concrete structural systems for seismic engineering

Research within the United States on seismic engineering of buildings using composite steel/concrete structural systems has increased dramatically in the past decade. This paper summarizes recent research on a number of these composite lateral resistance systems, including unbraced moment frames consisting of steel girders with concrete-filled steel tube (CFT) or steel reinforced concrete (SRC) columns; braced frames having concrete-filled steel tube columns; and a variety of composite and hybrid wall systems. The benefits of these structural systems relative to more common systems include their performance characteristics when subjected to service or ultimate loads, and their economy with respect both to material and construction. In addition, more in-depth research results will be presented on one of these composite systems, consisting of partially-restrained steel frames with composite reinforced concrete infill walls. The paper concludes with a summary of probable future design provisions for these composite systems.     

铁路隧道工程地质勘察及工程地质环境

通过采用地质勘察方法对隧道区域的地质环境予以全面系统的分析研究,探讨了监测隧道结构收敛变形情况,并对隧道工程进行了稳定性分析,为复杂地质条件的铁路隧道工程地质勘察提供一些参考依据。     

利用价值工程选择基坑围护方案和施工

某工程由于地块所处位置的特殊性，基础施工过程中的基坑安全和环境要求成为选择施工方案的首要目标，价值工程在选择基坑围护方案中的应用，使得方案决策的综合目标得到了很好地实现。