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0. 1 Characteristics of modern engineering construction and its requirements for engineering design

The pace of modernization in China is advancing by leaps and bounds. It is particularly urgent and necessary to re-understand modern architectural engineering and how to engage in modern engineering design, construction and management. Modern construction projects include a large number of civil construction projects, including industrial areas, residential areas and facilities related to production and life, including land, marine, industrial, civil and military projects. With the development of modern science and technology, all construction projects have the characteristics of the times, which requires the organization and management of engineering design and the means and methods of engineering design and construction implementation to have the characteristics of the times. Because the engineering construction starts from design, and the author has been engaged in design work, this paper re-examines and studies the modern engineering construction according to the characteristics of modern engineering buildings, focusing on engineering design.

0. 1. 1 Coordinated optimization of large-scale engineering systems with reliability as the index.

The characteristics of modern engineering construction require us to coordinate the engineering design of each subsystem with reliability indexes in order to achieve the goal of safe and efficient operation of large-scale systems. Modern construction projects are often huge in scale, such as the Three Gorges Project and the South-to-North Water Transfer Project, which cost hundreds of billions and take years or even decades. A common engineering project, such as factory, mining area, residential area or water conservancy and electric power hub project, has the following characteristics: it covers a large area, and some even exceed the previous towns and villages; In addition to the main building, there are often many supporting buildings, such as water pump room, power distribution room, management office, staff accommodation lounge and so on. There are multi-level systems, such as transportation system, water supply and drainage system, strong current and weak current system, air conditioning system and other subsystems, and it is these subsystems that constitute a complete large system. At present, the engineering design is carried out for each single structure. In fact, the engineering system pieced together after each structure is independently optimized (optimization is a basic feature of modern structural engineering design) is not necessarily optimal, just as the structure pieced together after each component is independently optimized is not necessarily optimal. To sum up, the optimization must proceed from the overall situation of the system in order to truly receive the optimization effect.

0. 1.2 Guided by functional objectives, the technical, economic and social environment shall be considered as a whole.

The characteristics of modern engineering construction require us to change the problem-oriented (technology-oriented) aspect of traditional design, and modern design should be function-oriented, taking into account technical, economic and social environmental factors comprehensively. The technical objectives and functional requirements of modern construction projects are becoming more and more complex, and the construction needs to be people-oriented. The design of building projects should start with the study of human activities. Food, clothing, housing and transportation are the most basic activities of human beings. With the development of the times and social progress, they also have richer contents and more distinctive features. Take "travel" as an example. Now it is not only a traffic problem, but also production, life, entertainment and social activities. "Tour the flowers" and "the scenery moves with the pace" represent people's two demands and hopes for travel, so people have different needs in material life and spiritual life around this activity and need different engineering facilities to match it.

As for more complex buildings, such as factories and mines, we should not only solve the production of individual products, but also promote the development of upstream products and downstream products, form an industrial chain, and achieve the goal of developing the economy to the greatest extent and solving people's employment. At the same time, sustainable development issues such as environmental protection and ecology must also be considered in the construction of factories and mines. Another example is the water conservancy project, which requires that the benefits of water conservancy, electric power, ecology, agriculture, forestry, fishery and animal husbandry, and environmental protection should be considered as much as possible. Even if a commercial and residential complex is built, it is necessary to comprehensively consider how many residential, commercial and office services it provides to the region and its impact on the city's environment, transportation, water supply, power supply, gas supply and heating. Modern architectural engineering is characterized by a wide variety of materials and equipment and high installation technical requirements. Modern construction projects are huge in scale and consume a lot of materials, and the varieties and specifications of materials are extremely complicated. Various pipeline specifications, diameters and varieties are varied, and some projects can reach thousands. Due to the continuous improvement of the modernization of life, more and more equipment is needed, such as visual doorbell and broadband network interface. The procurement, ordering, sending, receiving and keeping of these materials, equipment and equipment is a series of meticulous and planned work. (model essay. In addition, due to the improvement of mechanization of engineering construction, all kinds of construction machinery are needed to cooperate with the operation, and the installation process is becoming more and more complicated. Therefore, the construction sequence, walking route of construction machinery, working face, parallel operation and cross operation need to be considered in the design.

3 system evolution theory and the reliability of building structural engineering system in the aging period ................ 9

3. 1 New Three Theories of System Science ........... 9

3.2 Aging mechanism of building structural engineering ............. 1 1

3.3 ............. 13, a preliminary mathematical model for the reliability of building structural engineering system in aging period.

4 optimization of building structural engineering system-function and cost analysis ........... 15 ..

4. 1 system design-system analysis and synthesis ............ 17

4.2 Optimization of Building Structure Engineering System ........... 19

4.3 Analysis of the concepts of "optimization" and "optimization" .......... 2 1

5 Evaluation and decision-making of building structural engineering system-time and cost analysis ..........................

5. 1 systematic evaluation ............. 26

5.2 System Decision ........... 28

5.3 Overview of systematic evaluation methods ........... 30

5.4 Overview of system decision-making methods .......... 35

5.5 Evaluation and decision-making process of building structural engineering system .........................................

8 conclusion

Since Newton founded the classical mechanics theory system, the structural engineering has made great progress. The structural system has developed from the original wood structure, brick-wood structure and masonry structure to cast iron structure, reinforced concrete structure, steel structure and carbon fiber structure. The structure itself is developing in the direction of light (weight), thin (component size), large (span) and high (total height). All this seems to indicate that the development of structural engineering has come to an end. As long as architects can think of any shape design, structural engineers should be able to put it into practice. But this is not the case. First of all, a series of engineering accidents and their disastrous consequences can not but make people doubt the defects of structural engineering. Secondly, the infrastructure of modern cities and its lifeline construction projects constitute a huge and complex network system, and the failure of any key node may lead to serious derivative disasters, and its losses will be incalculable. How to ensure that this network system has enough ability to resist risks and disasters, and how to ensure the reliability level of this system? Obviously, mathematics and mechanics are not enough.

The emergence of modern new technology and the mutual penetration between disciplines make structural engineering explore new fields continuously. At present, emerging frontier disciplines, such as earthquake engineering, ocean engineering, nuclear energy engineering and wind engineering, are all interdisciplinary. Although structural engineering, as a traditional discipline with a history of hundreds of years, has to be open-minded and integrated into the theories, practices, methods and concepts of systems engineering, value engineering, thinking science, environmental science and aesthetics. At present, the development of structural engineering is also developing in the direction of expanding time domain and space domain. In the time domain, architectural engineering papers show that the design that only considers normal use extends to the comprehensive decision-making of the whole process including construction, use and maintenance. In the space field, the analysis of a single component extends to the comprehensive analysis and control of the overall structure and its disaster-related systems. This is the embodiment of the basic viewpoint of system science. The main content of this paper can be divided into three parts. The first part points out that structural engineering can and should be studied as a system because of its inherent characteristics, and the design, construction, use, maintenance and even scrapping of building structural engineering systems should be considered as a whole.

refer to

[1] Wang Guangyuan, etc., Practical Methods for Seismic Optimization Design of Engineering Structures and Systems, China Building Industry Press published the first edition in June 1999.

[2] Lin Tongyan? d？ Stotz Burry, translated by Gao Liren, Structural Concept and System, China Building Industry Press, 2nd Edition, February, 1999.

[3] Zhao Guofan Jin Gong, structural reliability theory, China Building Industry Press published the first edition in February 2000. ..

[4] Qu Wenjun, Reasonable Relationship between Durability of Concrete Structure and Design Base Period, China Water Resources and Hydropower Press published the first edition in May 2000.

[5] Zou Shangang, System Science, Shanghai People's Publishing House, first edition, 1987 1 1.

[6] Zhang Xichun, Standardization System Engineering, quoted from Superstar Online Library 65438+September 1 edition.

[7] Yao Demin et al., Practical Systems Engineering Course, quoted from Superstar Online Library, 2nd Edition, September, 1997.

[8] Liu Sifeng et al. Grey system theory and its application are quoted from Superstar Online Library, 2nd edition, September 1997.

[9] Wang Guangyuan et al. "Fuzzy Reliability Analysis of Engineering Structures and Systems" is quoted from the second edition of Superstar Online Library1September, 997.

[10] Ma Dexian's "Process System Artificial Intelligence Technology" is quoted from the second edition of Superstar Online Library in September 1997.