On December 13, 2017, after the Hengqin Comprehensive Pipe Gallery won the national first Luban Prize, China MCC20 Group Corp. Ltd had another good news: the Zhuhai Hengqin Headquarters Building (Phase 1) Project won the National Engineering Construction Quality Top Honor Award - National Quality Project Award!

The unexpected cold front-raid Zhuhai, the sunshine embraced and tall-building-surrounded Hengqin, the once banana-grown tidal flat, has now been covered by commercial buildings, industrial parks, schools, and wetland parks, which glittered against the winter sunshine. Zhuhai Hengqin Headquarters Building (Phase I), as the earliest completed 5A Class A commercial office building used on the island, silently stood at the Hengqin Port Business Center in the global fourth largest bay area - Guangdong-Hong Kong-Macao Greater Bay Area. Maybe, the building has not realized that as the first commercial building at the meeting point of "one country, two systems", the building had ignited a new wave of development and construction of Hengqin.

The Hengqin Headquarters Building on the east side of Hengqin New Area in Zhuhai faces the Macao SAR across the river. The project is constructed in two phases. It creates a gateway landmark of “Two Dragons Playing with Pearls” using the geographical advantage, integrating retail commerce, shopping malls, and dining and entertainment, cinemas, business offices and other functions. The Zhuhai Hengqin Headquarters Building (Phase I) is an about 160m super high-rise building. The gross floor area is approximately 106,981.9 square meters, of which the office floor area is 56,669.5 square meters, and the commercial floor area is 11,613.3 square meters. The core barrel-frame shear wall structure is used, with a total of 33 floors, of which 1-4F are commercial podiums, 5-32F are floors of the office building; the 33F is a top-level clubhouse. At present, it has become a new focal point and landmark for the riverside of Zhuhai Hengqin New Area and even the city skyline of Macao.

High starting-point planning, high standard construction

The MCC people wholeheartedly constructed Hengqin. In 2009, after two unsuccessful developments, Hengqin ushered in her third major development. This time, it met the “national metallurgical construction team, the main force for capital construction, and a leader in emerging industries.” MCC applied the rigorous thinking of industry to civil construction, overhauled roads, and built an integrated pipe gallery, and created a sponge city. Then, Hengqin Headquarters Building came into being.

At the early stage of the project, the MCC20 Group established the quality objective of Hengqin Headquarters Building Project achieving the National Quality Project Award in accordance with the principles of “high starting point planning, high standard construction, and high-quality management” set by the Hengqin New Area. The quality objectives were decomposed and implemented level by level and managed and controlled by hierarchy and with delicacy. A linkage system was established integrating the leadership of the project department and the quality, safety, material, and business systems, and a total staff, whole process, and all-around quality management working mechanism was formed. Detailed planning on project creating excellence was prepared, strict project management methods and quality internal control standards were formulated, and bright spot planning was implemented to ensure that the project quality was created into excellence at one time. Gao Yunfeng, the project manager, together with all the staff of the Project Department, gave up the rest time, read various high-rise building basic norms by using spare time, and held study seminar. Viewpoints from the leaders and staffs collided in the meeting room, making no distinction of their identities. Each was determined to overcome the difficulties of the project with high standards and strict requirements. The departments/offices also cooperated with each other, coordinated with and helped each other for the smooth accomplishment of the objectives.

Increased 20million yuan to reinforce the deep foundation pit

The foundation pit of the Hengqin Headquarters Building (Phase 1) Project is 478m in length and up to 18m in depth. The silt and silty soft clay distributed in the site was relatively thick, ranging from 11.1m to 14.5m, and featured low bearing capacity. In light of the complex geological structure, the Project Department braved the difficulties in construction, and pertinently organized engineering equipment including earthwork excavation and rock drilling tools and equipment, and heavy and light-duty submersible pumps and eliminated the influences on the excavation of the foundation pit from the rainy days in southern China. Meanwhile, the Project Department actively organized the construction cooperation units to increase input in staffing, held an engineering regular meeting at 9:00PM every night, made site inspection and supervision of the work of the day and arranged the work for the next day, and increased cooperative efforts among construction units and coordination and management and control of construction steps.

The deep foundation pit of the project has been equipped with effective supporting piles for maintenance. However, to ensure absolute safety, MCC20 insisted on the foundation pit supporting system consisting of underground continuous wall and internal support. Although the direct cost of foundation pit engineering increased by 20million yuan, the correctly selected protection system reinforced the deep foundation pit and laid a good foundation for the construction of the superstructure. Meanwhile, it facilitated the completion of the schedule for the basement construction without delay and saved the construction period by 2 years compared with the surrounding projects.

Technological innovation, saving 32.15million yuan

The technological innovation is the guarantee of project quality. The Hengqin Headquarters Building promoted use of 9 major and 18 sub-items of 10 new technologies in the construction industry, cumulatively saving comprehensive investment of 32,156,400 yuan. The new technology had advantages of wide application and high effectiveness. The topics on “research and application of complete sets of technologies for super-high-rise buildings in soft soil areas”, deep foundation pit support technology in deep soft soil layer, construction technology for rigid concrete, natural ventilation design and key technologies for unit curtain walls was appraised by MCC Group for the scientific and technological achievements, with conclusion that the comprehensive level had reached the domestic-leading level. In addition, 4 authorized invention patents had been received, including prefabricated reinforced concrete joint and connection method for underground continuous walls, the control device for the quality of in-plane concrete pouring and its application method, pre-crack grouting method for rock-socketed pile bottom, spiral stirrup positioning device, and the manufacturing method for rebar cage. 9 utility model patents had been received, including high-rise building roof curtain wall lifting tools, hydraulic grab attachment steel brush, anti-overflow irrigation device, a concrete vibration motor moving device, rebar threaded connection bracket, measuring instrument aerial bracket, separation devices of concrete of different grades for beams cross-sections, stiffening steel reinforcement pads, and vertical steel connection plates in steel structure buildings. Thanks to the bold introduction of new technologies and new methods for the project, the construction rate was greatly guaranteed. Through hard work and scientific acceleration of duration, finally the headquarters building was completed at leading construction rate and stood proudly on Hengqin Island. The capping of 33F building was successfully accomplished on December 17, 2014.

BIM technology application. This project uses BIM"s three-dimensional technology to conduct collision check in the early stage, to optimize engineering design, and reduce the possibility of erroneous loss and rework in the construction stage, thereby improving construction quality.

159m vertical rebar binding and concrete pumping

The Headquarter Building is in height of 159.1m. As there were many core tube walls and rigid steel columns, populated rebar in the shear wall, and many rebar penetrating holes, great influence on subsequent rebar binding from the steel columns, the rebar binding was difficult and the concrete vibration and pouring were even greater. The highest grade of concrete for frame columns and shear walls was C60. The continuity of pouring must be ensured during the placement of concrete. Therefore, the selection of pouring equipment and the quality control during construction were particularly important. The Headquarters Building project was implemented with the model guide system and adopted unified quality standards to regulate the quality behavior. The steel bar 32@150 at the bottom of the tower platform was arranged in two directions. The angle iron support frame was used to support the top bar of the pile cap during construction. The wall bars were connected either by lapping or strip rolled straight thread. These two methods limit the position using ladder bars to ensure that the double-decker steel bars are horizontal and vertical, and the spacing is even and correct. The basement walls were pull-connected using the steel pipe support and the steel cable in the process of steel bar binding to ensure positioning accuracy of rebar during binding. To ensure once creation of excellence of the engineering quality and meanwhile strengthen the supervision of the process, the deviation of section lifting, welding (thick steel plate welding technology), installation of reinforcing steel, and the concrete cover were adjusted from time to time, and the measures for quality control were effectively implemented to eliminate quality defects.

Construction of 27 MEP pipeline systems

The system of this project is complex. There are 27 systems e.g. air-conditioning system, communication network system, office automation system, and security system. There are many intersecting disciplines, complex pipeline layout, deep construction and difficult site coordination. Therefore, effective measures must be taken during construction to ensure the safety and quality of the project. The BIM 3D technology was used to optimize the piping layout scheme in the early period. The 3D pipeline scheme after optimization of collisions was used to carry out the construction disclosure and the construction simulation to improve the construction quality.

5A Class A Business Commercial Building Decoration Standard

As the first 5A Class A Office Building in Hengqin, Zhuhai, the project requires simple and neat design style with high standard of decoration. Gypsum board ceilings were used in public areas, dry hanging stones were selected for the walls, and natural stone pavements were used for the floors. Aluminum gusset ceilings were selected for the office area, the walls were coated with paint, and the floor used cable elevated floor. The aesthetics of stone patchwork was one of the key points of construction. The interior wall finish of the tower was designed as dry hanging rusty stones. The entire wall surface is assembled from small stone blocks. While ensuring safety and quality, the deepening of the decorative drawings and the layout of stone materials must be performed. Through the joint efforts of all staff, the project achieved the goal that any stone could not go wrong. The lobby wall adopted natural marble mosaic technology, featuring no color difference, aesthetic and elegant. The public area stone walls were firmly installed, and must have straight joints, and the uniform width. The reception desk used ecological green background walls and was full of vitality.

National AAA Safety, Civilized and Standardized Site

The Project Department takes “never construct at the cost of the environment” as its own responsibility, always puts environmental protection in the first place during organization of construction management and takes technical innovation and the environmental protection as the main line, implements job responsibilities, and strengthens various measures. In term of pollution control, noise reduction, sewage and airborne dust control, the Project Department must ensure that environmental protection is under control in accordance with the "four-savings and one environmental protection" requirement put forward by the Group. The exterior wall of the Headquarters Building was designed with 200-thick aerated concrete masonry and composite aluminum sandwich panel walls. The exterior windows and glass curtain walls were made of LOW-E hollow tempered glass, and the roof insulation layer was 40-thick extruded polystyrene foam panels. The glass curtain wall adopted double-silver low-e insulating glass, which reduced noise, permeability, high energy consumption, and reduced the heat loss by nearly 90%. The side air inlet installed in the unit-type curtain wall could realize natural ventilation and meet the ventilation requirements in spring and autumn without affecting the exterior wall appearance. The energy saving effect of the engineering design was significant. By "greening in every bit of available space" in the vicinity of the project office area and temporary construction housing, a "garden-style" site was created. Through a series of effective measures, the project won many honors in 2015, including the Guangdong Provincial Housing Municipal Project Safe Construction Civilization Construction Demonstration Site, the Fourth Batch of National Construction Industry Green Construction Demonstration Project and the highest national award for safe and civilized construction - National AAA Safe, Civilized and Standardized Site.

MCC20 won the national quality project award for the first time in the fields of the super high-rise civil building. It is the starting point for embarking on the new journey of transformation and the mission that the era has endowed to the MCC20. The road of super high-rise brand has only just taken off. We will continue to adhere to the simple and profound MCC spirit of “Never delaying and never slacking”, embark on broader stage with passionate attitude, and continue to make its due contribution to the "MCC people cast the world attentively”.

　　(Guangdong Branch Liu Jiwei, Liu Shihua　Text)