HY-1C Coastal Zone Imager observations of the suspended sediment content distribution details in the sea area near Hong Kong-Zhuhai-Macao Bridge in China

The impacts of the Hong Kong-Zhuhai-Macao Bridge(HKZMB)on suspended sediment content(SSC)were analysed in the Zhujiang River Estuary based on data from HY-1C,which was launched in September 2018 in China,carrying Coastal Zone Imager(CZI)and Chinese Ocean Color and Temperature Scanner on it.A new SSC inversion model was established based on the relationship between in-situ SSC and the remote sensing reflectance in red and near-infrared bands of CZI image.HY-1C satellite data obtained from October to December 2019 were applied to retrieve SSC in the Zhujiang River Estuary.The results show that SSC around the HKZMB is ranging from 20 mg/L to 95 mg/L.SSC change obviously on two sides of the bridge.During flooding and ebbing period,SSC increases obviously downstream of the bridge.SSC difference between upstream and downstream is ranging from 5 mg/L to 20 mg/L.Currents flowing across the HKZMB,the change trend of SSC in most places upstream and downstream is almost the same that SSC downstream of the bridge is higher than SSC upstream.The tidal currents interact with bridge piers,inducing vortexes downstream,leading the sediment to re-suspend downstream of the bridge piers.Other factors,including seafloor topography and wind,can also contribute to the distribution of SSC in the Zhujiang River Estuary.

Drivability of Large Diameter Steel Cylinders During Hammer-Group Vibratory Installation for the Hong Kong–Zhuhai–Macao Bridge

The Hong Kong–Zhuhai–Macao Bridge(HZMB)involved the installation of 120 mega-cylinders with a diameter of 22 m,weights up to 513 t,and penetration depths up to 33 m using an eight-vibratory hammer group.Due to the lack of engineering experience on the drivability of large-diameter cylinders under multiple vibratory hammers,predicting the penetration rate and time of steel cylinders is an open challenge that has a considerable impact on the construction control of the HZMB.In this study,the vibratory penetration of large-diameter steel cylinders in the HZMB is investigated based on geological surveys,field monitoring,and drivability analysis.The vibratory penetration rate,installation accuracy,and dynamic responses of the steel cylinders at both the eastern and western artificial islands are analyzed.The dynamic soil resistance has a great influence on the cylinder drivability.However,the current design methods for estimating the vibratory driving soil resistance are proven inaccurate without considering the scale effects.Therefore,a modified method with a normalized effective area ratio A_(r,eff)is proposed in this study to calculate the vibratory soil resistance for open-ended thin-wall cylinders under unplugged conditions.Considering the scale effects on the vibratory driving soil resistance,the proposed method leads to closer results to the measured data,providing a reference for future engineering practice.

Pavement structure and materials design for sea-crossing bridges and tunnel:Case study of the Hong Kong-Zhuhai-Macao Bridge

With the continuous development of bridge and tunnel construction technologies,large-scale sea-crossing bridges and tunnels have gradually become the preferred choice for regional traffic.The construction technology of Hong Kong-Zhuhai-Macao Bridge(HZMB),one of the most representative sea-crossing passageways,is instructive for the construction of other large sea-crossing infrastructures.At present,the pavement design method of sea-crossing passageways lacks pertinence as it still refers to specifications for design of common pavement.Therefore,it is necessary to consider the bridge and tunnel pavement of HZMB as a typical example to analyze key technical problems encountered in its design,construction and operation.Novel solutions for material selection and structural design built upon the analysis of such critical problems should thus follow up.Based on comprehensive literature research,it can be found that environmental variability,tunnel closure,structural differential settlement and expansion deformation are the key technical problems faced by pavement of sea-crossing passageways.In view of the environmental variability,the steel deck-paving material and structure design of GMA-10 t SMA-13 is innovatively proposed.As for the closure of immersed tube tunnel,warm-mix flame retardant asphalt mixture is used to control pavement design through key indexes such as temperature and limit oxygen index.Regarding the deformation of immersed pipe joints,BJ200 asphalt seamless expansion joint material is introduced,which effectively satisfies the multi-directional deformation between pipe joints and ensures the smoothness of the road surface and driving comfort.For segmental joints,double-layer waterproof-coiled material is used to effectively prevent reflective cracks while ensuring the continuity of asphalt concrete pavement.Therefore,this paper provides a panel of ideas and methods for the pavement design of the same type of sea-crossing passageways.

The design philosophy and bridge＇s technical innovation of Hong Kong- Zhuhai-Macao Bridge

This article introduces the project overview, construction goal and design philosophy of Hong Kong- Zhuhai-Macao Bridge. Based on large scale, factory production, standardization and assemble line, the innova- tive concept is taken as the general principle for design with the emphasis on description of the new material, new technology, new construction method and new equipment used in the design. The application of innovative technology has provided a solid foundation and favorable guarantee for project quality and design service

How does the improved DB mode degrade the complex integrity of infrastructure mega-projects？ Evidence from the Hong Kong-Zhuhai-Macao Bridge project in China

Complex integrity is one of the main characteristics of infrastructure mega-projects(IMPs). Cost,technology, risk, duration, environmental impact, and other uncertain complexities are interrelated and constitute a challenging and complex management problem. At present, there is no unified understanding of or solutions to these complex integrity problems. This study analyzes the complex integrity of the island-tunnel subproject of the Hong Kong-Zhuhai-Macao Bridge(HZMB) project and proposes an improved design-build(DB) mode in which the owner provides a preliminary design and has the right to form and manage consortium. This improved DB mode creatively degrades the special complexities that arise from multiple dimensions. On this basis, it is an efficacious way to grasp the main contradictions, integrate the effective resources, and degrade the complex integrity in multiple dimensions and at multiple levels so as to effectively deal with the complexity management of IMPs.

A fuzzy model for assessing the risk exposure of procuring infrastructure mega-projects through public-private partnership： The case of Hong Kong-Zhuhai-Macao Bridge

Considering the rapid urbanization growth rate particularly in developing countries, the number of infrastructure mega-projects over the past years has risen tremendously. Essentially, because infrastructure megaprojects require huge investment funds, better management skills, well qualified and experienced international expertise and technology innovation, they are mostly preferred to be procured using the PPP method compare to the use of the traditional bid-build system. In this regard, this paper aims to develop a fuzzy evaluation model for assessing the suitability of procuring infrastructure mega-projects through PPP by considering their risk exposure. The main body of Hong Kong-Zhuhai-Macao Bridge(HZMB)is used as a case project to demonstrate the practicality of the risk evaluation model. The risk evaluation model consists of four critical risk groupings, these include,construction and land risks, commercial risks, operational risks and political risks. Using the risk evaluation equation,a risk index of 4.53 out of 5.00 is computed for the selected project if it is procured through the PPP scheme. This outcome shows that the case project is not suitable for the PPP approach because its risk exposure is very high. The model developed will enable PPP practitioners to predict the likely risk exposure of procuring infrastructure megaprojects through the PPP scheme.

Meta-synthesis management framework of a complex project： A case study of the deck pavement project of the Hong Kong-Zhuhai-Macao Bridge

Innovative technology and deep uncertainty during the design and construction process of complex projects introduce great challenges to their organization and management.The traditional methods,represented in the project management body of knowledge(PMBOK)guide,can solve systematic problems;however,they cannot solve complex problems.Based on the management practice implemented in the deck pavement project of the Hong Kong-Zhuhai-Macao Bridge(HZMB),in this work,we propose a meta-synthesis management framework for a complex project from the perspective of the science of complexity.The method deems that the complexity of the project has the characteristic of being multi-scale both in the design phase and the construction phase.These problems can be classified into different categories,each of which requires a different strategy.As a result,it is first necessary to adopt the"exploration"strategy to reduce project complexity and to transform the deep uncertainty problems into systematic problems.Then,the"exploitation"strategy should be used to apply the PMBOK and other traditional methods to achieve the design and construction goals of the project and to improve its efficiency.More specifically,in the design phase of a complex project,the"innovative integration"process is used for the exploration of the new engineering technology and knowledge;then,the"functional integration"process is employed to define the system architecture,the interface relationship,the technical index,and other functions.In the construction phase,the"adaptive integration"process is used for the construction of the engineering organization system;next,the"efficient integration"process is employed to improve the actual construction performance.The meta-synthesis management framework proposed in this work reveals the multi-scale principle of solving complex problems in the management practice of a complex project,and develops the methodology of metasynthesis.

Social responsibility in infrastructure mega-projects： A case study of ecological compensation for Sousa chinensis during the construction of the Hong Kong-Zhuhai-Macao Bridge

Ecological compensation plays an important role in implementing the social responsibility of infrastructure mega-projects. Based on the results of a field study, an in-depth interview, and archive data, this paper introduces the ecological compensation for Sousa chinensis(the Indo-Pacific humpbacked dolphin) during the construction of the Hong Kong-Zhuhai-Macao Bridge. It studies the concrete measures, decision-making processes,and organizational collaboration of the ecological compensation, using the method of a case study. The present study not only enriches our understanding of the ecological compensation practice during the construction of infrastructure mega-projects, but also extends the literature on the social responsibility of infrastructure mega-projects.This sheds light on the protection of the environment as well as biodiversity in the construction of future infrastructure mega-projects.

Coupling and evolution mechanism of infrastructure mega-projects complex ecosystem： Case study on Hong Kong-Zhuhai-Macao Bridge

Infrastructure mega-projects(IMP), which involve complex interactions and feedback, have more significant impact on economic, social, and other systems.This paper proposes a concept—the IMP complex ecosystem—to analyze IMP from a broad perspective of organic links across engineering, social, economic, and resource environments. Moreover, this paper proposes the theoretical concept, framework, and functions for the IMP complex ecosystem based on complex ecosystem theory.First, the coupling process between IMP complex ecosystem subsystems is analyzed through material flows, energy flows, information flows, and value streams.Second, a logistic model of the IMP complex ecosystem is proposed by analyzing the evolution conditions and motivations. Third, the evolution pattern of the IMP complex ecosystem is determined. Fourth, the positive evolution strategy of the IMP complex ecosystem based on dissipative structure theory and the influencing factors of the evolutionary process is introduced. Finally, the Hong Kong-Zhuhai-Macao Bridge and Sousa chinensis are used as the case study. This paper also analyzes the coupling structure on the complex ecosystem of the Hong KongZhuhai-Macao Bridge and investigates the coupling and evolution mechanism application of the IMP complex ecosystem on Sousa chinensis protection for the Hong Kong-Zhuhai-Macao Bridge project.

To Promote the Communication of Talent in the Greater Bay Area

The opening of the Hong Kong-Zhuhai-Macao Bridge and the Guangzhou-Shenzhen-Hong Kong Highspeed Railway improved the connectivity of the Guangdong-Hong Kong-Macao Greater Bay Area by shortening the driving time between the three areas within one hour,and injected new momentum into regional economic development.As a central city of Guangdong-Hong Kong-Macao Greater Bay Area,Hong Kong has established closer connections with the mainland through the Hong Kong-Zhuhai-Macao Bridge and high-speed railway,and unlocked new potential for the implementation of the Belt and Road Initiative.Under the current international environment of competitiveness,to build a world-level Bay Area with great vigor and vitality requires the fostering of a positive environment for talent both in China and abroad,in which their ingenuity and expertise flow freely.

中国港珠澳大桥多角度锚箱加工工艺

锚箱是斜拉桥的重要组成部分,通过锚箱将载荷传递到斜拉索上。以我国建成的港珠澳大桥为例,基于π型组焊件的三维分量新特点,从翻转、固定、角度测量等因素出发,设计制造了一套多角度翻转工作台,成功实现了多角度锚箱机加工。改进后的工艺使得加工精度提高了一倍以上,顺利通过了验收,为各种形式的斜拉桥锚箱制造开辟了新方法。