Foreword by Jun Sun

In recent years，the development of infrastructure construction in China has been developing vigorously.The construction of“The Belt and Road”has been continuously promoted.Many major projects have mushroomed vigorously，such as the Three Gorges Project，the Qinghai-Tibet Railway，the South-to-North Water Diversion，the three vertical and four horizontal high-speed rail network，the Hong Kong-Zhuhai-Macao Bridge，Shanghai Center Tower，and the construction with China's aid of the Jakarta-Bandung high-speed railway，the China-Laos railway，the China-Thailand railway，the Gwadar Port，the Piraeus port and so on.There is no doubt that China has become one of the countries with the largest number of major projects in the world.In terms of construction scale，technical difficulty and capital investment，these major projects are among the top not only in China，but also in the world，and even in the first place.A series of major key technical problems emerged in the construction process of these projects，many of which have been well optimized and solved through analysis，exploration and innovation.Some even created new technical means and methods on the basis of the original theory and technology，and applied for a large number of technical patents.For example，Shanghai Center Tower，632m，as the world's tallest green building，has achieved many scientific achievements in many aspects such as super high-rise design，green construction，construction supervision and building information modeling（BIM）technology.It has applied for 8 invention patents and authorized 12 practical new technologies.Only in the aspect of structural engineering，it has been applied to many innovative technological innovations，such as the support technology of super deep foundation pit，the technology of super high pumping concrete，the installation technology of complex steel structure and the technology of structural crack control，some of which have reached the world level.These optimizations，breakthroughs and innovations will be very valuable references for Chinese engineers and technicians.

During the plenary session of the National People's Congress held in early March 2016，many representatives said that a great deal of technological innovation and development is a key driving factor for realizing China's macroeconomic strategic adjustment during the 13th Five Year Plan period，and a fundamental support and key driving force for realizing the overall development of the country under the overall layout.

At the same time，in the face of the opportunity of a new round of scientific and technological revolution，only by making innovations and breakthroughs in key core technologies one by one can we realize the overall leap of social productivity，make the level and ability of our scientific research achievements and engineering technology control enter the ranks of developed countries as early as possible and as quickly as possible，so as to continuously improve the technological competitiveness in the world，and the national strength will be stronger！At present，many engineering technology innovations have been widely recognized，but there are still many problems in the promotion and application of innovation results.In the field of major engineering construction，after the key engineering technical problems have been broken through and solved in practice，it is necessary to further sort out and summarize the new theories or methods，and then widely apply them to production practice again，which in turn will promote further innovation and development of technology，which is a huge driving force for the sustainable development of technology.One of the most effective aspects is to systematically summarize the innovative achievements and publish a set of technical monographs.This is also the significance of publishing the series of“Research on Key Technologies of Major Engineering Construction”.With the promotion of academic innovation as the main goal，the series of“Research on Key Technologies of Major Engineering Construction”has the following characteristics：

（1）Focus on major projects and key projects.At present，China's infrastructure construction is booming in various fields，and various kinds of engineering projects continue to mount.From the perspective of project volume and technical difficulty，we have selected a number of major projects and key projects，based on which，we have summarized the professional theory and technology to make them into books.Due to the large number of fields and disciplines involved in various projects，and the intersection and integration of disciplines，it is difficult to set a series of books with a single discipline.Therefore，based on the main line of Engineering categories，a series of books have been written in eight fields，i.e.，tunnel and underground engineering，bridge engineering，railway engineering，highway engineering，super high-rise and large-scale public buildings，water conservancy engineering，port engineering，urban planning and architecture，basically covering the main fields of engineering construction in China，with a view to providing professional and technical reference guidance for major engineering construction in the future.As there are many fields and specialties involved，there are similarities and differences between technologies.In the field of cross technology，they are dealt with according to the specific situation to avoid content duplication and disjunction.

（2）Highlight common technology and innovation achievements，and focus on application technology theorization.Focusing on a series of key technical problems in major projects in recent years，and based on the innovation achievements and technological breakthroughs made by the project，the series of books sort out pertinently the technical experience and scientific research achievements of common，key or significant promotion value in each series，and makes indepth，systematic and detailed analysis and elaboration from the perspective of technical methods and engineering practice experience，and provides practical theoretical basis and application reference for the solution of similar problems and the improvement of technology.In the“Series of Key Technologies for Tunnel Construction under Complex Geological and Environmental Conditions”（Academician Qihu Qian is the director of the editorial board），the key problems in the current tunnel and underground engineering construction are systematically described and the corresponding professional technical theory system is formed，including the prediction，warning and risk control of major water inrush disaster in deep and long tunnels，the treatment of soft and hard uneven stratum and extremely soft stratum in shield engineering，a sort of rectangular shield method，underwater shield tunnel，ground access shield method tunnel，extra-long highway tunnel，three-dimensional geological detection of tunnel，rapid detection of shield tunnel disease，digitalization of tunnel and underground engineering，new anchorage material for large deformation tunnel in soft rock and so on，and the key problems are solved in different degrees in the research and effectively implemented in the follow-up project.

（3）Pay attention to the practical value of the project.The technical achievements involved in the series have been adopted many times in China，which have been proved to be reliable and effective in practice，and some of them have obtained technical patents.The series emphasizes the theory as the guide，the application as the key，and the case as the illustration.All the technical achievements are required to take the engineering project as the background and the production practice as the support，so that the series not only has the academic connotation，but also has the important engineering application value.For example，the“Series of Key Technologies for Long-span Bridge Construction and Maintenance”（academician Jielian Zheng is the director of the editorial board，academician Zhengqing Chen is the deputy director），focusing on major bridge projects such as long-span suspension bridges，long-span bridges across the sea，multi tower cable-stayed bridges，long-span concrete-filled steel tube arch bridges，long-span pedestrian bridges，large-scale spatial suspension bridges with variable width，etc.，focuses on the design innovation theory，construction innovation technology，technical breakthrough of construction difficulties，bridge structure health monitoring and state assessment，maintenance and maintenance during operation period，etc.The main contents include the vacuum assisted pouring technology of large-scale concrete-filled steel tube structure，the spatial cable plane suspension bridge system with large proportion and variable width，the new eddy current damping vibration reduction technology，the cable hoisting and cable-stayed buckle construction of long and large bridges，the super large-scale deep-water foundation super high composite bridge tower，intelligent deformation monitoring，and the integration of construction and maintenance based on BIM，etc.These technologies are based on major construction projects，including the first bridge of Hejiang Yangtze River，the second bridge of Hejiang Yangtze River，Wushan Yangtze River Bridge，Nanpanjiang bridge of Guangxi Guangzhou railway，Zhangjiajie Grand Canyon bridge，Xihoumen Bridge，Jiashao bridge，Hong Kong-Zhuhai-Macao Bridge，Humen second bridge，etc.in the book，the relevant contents of specific project cases are analyzed in detail，with good application reference Test the value.

（4）Focus on the hot spot，focus on risk analysis，disaster prevention and mitigation，health detection，engineering digitization and other emerging branches in recent years.Under the guidance of the principles of green and sustainable development，in recent years，technological innovation in the field of infrastructure construction has many achievements and examples in energy conservation and emission reduction，low-carbon environmental protection，green civil engineering，risk analysis，disaster prevention and mitigation，health detection（remote wireless video monitoring），safety and economy in the life cycle of the project，reliability and durability，construction technology organization and management，digitization，etc.Series of books are also reflected in these aspects，in order to give full play to the role of series books in promoting the long-term，green and sustainable development of major project construction.

（5）Establish an open framework.As a result of the above characteristics，the progress of each volume of the series is different，so the open framework is adopted，and the flexible way of publishing in stages is adopted in the setting of each volume of the subsequent series.

（6）The editor in chief has first-class academic level，which lays a solid foundation for the academic quality of the series.The chief editor of each series is the academic authority in this field and has an important academic status and influence in this field.For example，Prof.Zhengqing Chen，academician of Chinese Academy of engineering，chief scientist of Project 985，bridge structure and wind engineering expert，Prof.Jielian Zheng，academician of Chinese Academy of engineering，bridge design and construction expert，Prof.Qihu Qian，academician of Chinese Academy of engineering，protection and underground engineering expert，Prof.Zhiqiang Wu，academician of Chinese Academy of engineering，urban planning and construction expert，etc.The main writers who participated in the writing were all the front-line personnel active in the research，education and engineering of infrastructure construction in China，who had undertaken major engineering construction projects or national major scientific research projects，mainly from China Railway Tunnel Bureau Group Co.，Ltd.，CCCC Tunnel Engineering Bureau Co.，Ltd.，China Railway Construction Co.，Ltd.，CCCC highway planning and Design Institute Co.，Ltd.，and the army Institute of engineering design，Qingdao Metro Group Co.，Ltd.，Shanghai Urban Construction Group，China Merchants Chongqing Communications Research and Design Institute Co.，Ltd，Tianjin Urban Construction Group Co.，Ltd.，Zhejiang Communications Planning and Design Institute，Tongji University，Hehai University，Southwest Jiaotong University，Hunan University，Shandong University，etc.In addition to undertaking the heavy tasks of engineering construction and scientific research and teaching，all experts have contributed their wisdom，knowledge and sweat to the progress of engineering technology in China.On behalf of the General Editorial Committee of the series，I would like to express my heartfelt thanks and respect for your hard work.

At present，not only the domestic infrastructure projects are in the ascendant，but also under the initiative of“The Belt and Road”，China's major overseas projects are booming，and the demand for high level engineering technology is becoming increasingly urgent.It is believed that the publication of the series of books can provide certain assistance for the development of major engineering construction and the progress of innovative technology in China.

Shanghai，China　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　Jun Sun

December 2017

Mr.Jun Sun first-class Honorary Professor of Tongji University，senior academician of the Chinese Academy of Sciences，well-known expert in geotechnical mechanics and engineering at home and abroad.Chief editor of the series Research on Key Technologies of Major Engineering Construction.