On the morning of Oct. 23rd, the opening ceremony of the HongKong-Zhuhai-Macao Bridge was held in Zhuhai, Guangdong Province. President XI Jinping attended the ceremony and announced that the Bridge was officially opened to traffic. (Photo by JU Peng, Xinhua News Agency Reporter)
Collective Principal Contribution Medal Awarded to NHRI
Physical Modelling of Serial Key Technologies of Water-Sediment Movement and Structural Scouring of the Hong Kong-Zhuhai-Macao Bridge
Letter of Thanks (2017)
The Hong Kong-Zhuhai-Macao Bridge
On Oct. 23rd, 2018, the Hong Kong-Zhuhai-Macao (HZM) Bridge, which was called "one of the Seven Wonders of the Modern World" by the media, was officially opened. It was officially opened to traffic on the 24th. Chinese President XI Jinping attended the opening ceremony on the morning of the 23rd, announcing the official opening of the bridge and patrolling the bridge. On behalf of the Party Central Committee, he expressed his heartfelt gratitude and sincere greetings to the people who had participated in the design, construction and management of the bridge.
The HZM Bridge spans the Lingdingyang Bay, east to the Hong Kong Special Administrative Region, and west to Zhuhai City, Guangdong Province and the Macao Special Administrative Region. Its total length is about 55km, with its main work “bridge-island-tunnel” of 36km long and submarine tunnel of 6.7km long. It is the first extra large-scale cross-sea traffic engineering jointly built by Guangdong, Hong Kong and Macao under the framework of "One Country, Two Systems". The opening of the Bridge is of great significance to the construction of the Greater Bay Area of Guangdong, Hong Kong and Macao.
The HZM Bridge crosses the Pearl River estuary at the Lingdingyang Bay. The upper reaches are the main hub ports of South China, such as Guangzhou Port and Shenzhen Port, as well as important ports in the Pearl River Delta, such as Humen Port and Zhongshan Port. There are large-scale deep-water channels, such as Guangzhou Port Seaway, Tonggu Seaway in Shenzhen West Port Area, and important waterways, such as Qingzhou Waterway and Jiuzhou Port Channel in the bridge area, which is one of the most densely navigable water areas along China's coastal route. The dynamic geomorphologic pattern of “four estuaries into the sea” and “three tidal flats and two troughs” in the estuary of the Lingdingyang Bay makes water-sediment movement environment extremely complicated. The construction of the bridge faced a series of problems such as the bridge site, setting of main navigation area, optimization of artificial island plane, and reasonable span of bridge opening. The research on the impacts of the project on the water-sediment environment and port channel is particularly critical.
NHRI has given full play to its technological advantages. As early as the feasibility study stage of the HZM Bridge during 2004 and 2007, the analysis and calculation of hydrological elements of the proposed bridge area and the analysis of the seabed evolution were carried out, and the design wave, velocity and water level of the bridge area were proposed. The characteristics of natural environment, overall dynamic structure, the characteristics of water-sediment movement and their interactions were discussed. The evolution of seabed erosion and deposition in the bridge area was systematically summarized. From the perspective of satisfying the navigation conditions and maintaining the tidal flats and troughs, the opinions on site selection of the bridge were put forward, providing the basis for the preliminary design bidding of the project. During this period, NHRI also completed a special study on the numerical simulation of water and sediment in the site selection scheme of the bridge, and provided multiple options for the selection of the locations and shapes of the bridge, tunnel and artificial islands in the navigation area of the bridge. Based on the determination of the northward shift of the North Bridge, a plan for the rational arrangement of the artificial islands for “three inspections by respective governments of the three cities” and the use of wide-mouth gates for the artificial islands were put forward as well.
At the stage of further study on engineering feasibility and primary design from 2008 to 2010, NHRI project team did a number of special studies, including 2D and 3D tide, current and sediment numerical modelling, a wide range of hydrodynamic and sediment physical modelling, serial model tests of local scouring in wide flume, local scouring model test of bridge piers, physical modelling of wave-current force on bridge foundation, integral wave model test of artificial islands and the junctions between island and tunnel, and between island and bridge, integral physical modelling of local scouring of artificial islands, model test of artificial island section, hydrological analysis and computation, and field test of trial excavation. Comparison tests and analyses were carried out on the plane layout of the bridge, structural design scheme and stability of base groove, which made the layout scheme of bridge-island-tunnel more reasonable. Under the guidance of model tests, the artificial island plane and structure were optimized by changing from original long shape to oval shape, and shortening the width of upstream face from original 1000m to 625m. The research results provided key technical support for the national approval of the feasibility study report of the HZM Bridge project, and the review of the preliminary design plan for the main construction of the bridge by the Ministry of Transport.
Since the construction of island-tunnel project started in 2010, NHRI has mainly carried out a series of special studies, including the overtopping control measures of artificial island, main engineering of the bridge, hydrological analysis and hydrodynamic simulation model of island-tunnel construction period, physical model test of the artificial island at Hong Kong Customs, digital model test of the submerged area cover scheme at the junction between the east artificial island and tunnel, analysis of local sudden deposition in the base groove for immersed tubes of E15-E33, calculation of wave element of west artificial island under extreme weather conditions, and local and integral physical modelling of island-bridge junctions. The research results provided important technical support for artificial island structure safety, immersed tube placement, steel cylinder construction, and design and construction of cover body for island head. When the tube E15 installation process was impeded due to abnormal back siltation in 2014, NHRI sent its sediment experts to tackle the problem immediately, working together on countermeasures. The method for predicting basic back siltation under the joint function of tide, wave and runoff was proposed. Combined with field observation data, daily and centimeter-level fine sedimentation and back siltation prediction was realized providing continuous guarantee for the smooth installation of E15 and subsequent 18 immersed tubes. In view of the complex water and sediment problems encountered during the installation of the immersed tube at the junction between the east artificial island and tunnel, NHRI organized marine flow and sediment experts to carry out a large number of numerical modelling and analysis, providing a key basis for the design of the cover body in the east island head region. At the same time, a special study on the sea current and back siltation problem of tunnel closure was carried out, which provided important support for the smooth lifting and installation of the final joint.
NHRI participated in the key technical researches on foundation improvement of the artificial islands of the HZM Bridge as well. Through laboratory geotechnical tests, centrifugal model tests and numerical simulations, such following tasks were carried out as researches on long-term deformation rule of artificial island foundation, researches on stresses, deformations and stability of typical sections of artificial island foundation, analyses of seepage flow and permeable stability during construction, and of coordinated deformation between improved area of foundation and surrounding connected section. The deformations and stability properties of the artificial islands under various treatment schemes of foundation were released during construction and operation periods. Measures were proposed for controlling and improving the post-construction foundation settlement of the artificial islands. The research achievements provided theoretical and technical basis for the design and construction of foundation improvement of the artificial islands of the HZM Bridge.
NHRI was also invited to compile the technical proposal Durability Assessment and Experimental Study on Concrete Durability of the Hong Kong-Zhuhai-Macao Bridge, providing the long-age experimental data of concrete exposed in real marine corrosive environment in Zhanjiang Port, Guangdong Province and Basuo Port, Hainan Province, which were used as reference in the concrete durability design of the HZM Bridge. During the construction period, our experts were appointed to participate in the meetings many times on the engineering full scale experiment and construction schemes of the immersed tubes and hidden bridge in the artificial islands, and on the technical evaluation of concrete durability design, contributing our wisdom to ensuring the 120-year life of the HZM bridge.
The General Manager Department of the Island-Tunnel Engineering Project was grateful to NHRI for its technical and talent support by sending two Letters of Thanks in 2015 and 2017, respectively. In 2015, NHRI task group won a Collective Principal Contribution Medal due to its solution to the back siltation around E15 immersed tube. The research results of Study on Impacts of the Hong Kong-Zhuhai-Macao Bridge on Water-Sediment Environment of the Lingdingyang Bay and Port Waterway, completed by NHRI, won the First Prize of 2016 China Water Transport Construction Science and Technology Award. Study on Excavation Process and Back Siltation Observation Tests of Immersed Tube Base Groove of the Hong Kong-Zhuhai-Macau Bridge won the First Prize of Science and Technology Award of China Water Transportation Cnstruction Association in 2011. Research, Development and Application of Monitoring, Early Warning and Forecasting System of Immersed Tube Base Groove of the Hong Kong-Zhuhai-Macao Bridge won the First Prize of Science and Technology Award of China Institute of Navigation in 2017.
