The national quality project of China Construction Engineering Luban Award is not only a quality project, but also a high-tech project. In the process of creating excellence, construction enterprises not only improve their comprehensive management and quality management capabilities, but also sublimate their scientific research and technological innovation capabilities, enhance their market competitiveness and improve their economic and social benefits. The following is a brief introduction to the application example of new technology in the national quality project review of 20 10 Luban Award. 1 application of vibro-replacement gravel pile and concrete cast-in-place pile in sandy soft soil foundation; vibro-replacement gravel pile is an effective means to strengthen soft soil foundation and improve its vertical bearing capacity, and it is widely used in most areas of China. Vibro-replacement gravel pile mainly strengthens the foundation by forming dense piles and compaction in the foundation and forming composite foundation with the original foundation, so as to improve the bearing capacity of the foundation, reduce settlement and prevent structural cracks. It has the advantages of reliable technology, simple operation, greatly improving the bearing capacity of composite foundation, saving materials, fast construction speed and saving investment. Yulin International Hotel integrates tourism, conference and entertainment, with a total construction area of 65 294.49m2. The main building is a frame-core tube structure, with 27 floors underground 1 floor and a total height of 99m. The foundation of this project is located in fine sand and medium sand strata in desert area, and the foundation soil is soft, so it is difficult to treat the foundation. In order to ensure the safety of buildings and prevent the foundation from sinking, the following measures are taken: ① 732 vibroflotation gravel piles with a diameter of 900mm and a length of 6.5m are adopted to improve the bearing capacity of the foundation; (2) Using 744 plain concrete cast-in-place piles with a diameter of 350mm and a length of 4m, arranged in a plum blossom shape; (3) The building floor adopts a raft foundation, and vibro-replacement gravel piles, plain concrete cast-in-place piles and foundations form a complete composite foundation. In this project, vibro-replacement gravel piles and plain concrete cast-in-place piles are used to strengthen soft foundation, which plays an important role in improving foundation bearing capacity, enhancing building foundation stability and reducing foundation settlement. There are 25 settlement observation points in this project. After 4 1 settlement observation, the maximum settlement is 17.60mm, the minimum settlement is 1 1.54mm, and the total settlement rate is 0.0025 mm/d. After more than one year of use, no uneven settlement is found. The application of this technology provides valuable experience for the foundation treatment of high-rise buildings in desert areas and soft soil areas. 2 large area ground settlement prevention technology in soft soil area. A large area of concrete floor is generally constructed after backfilling in the center of the room. The density of backfill soil has a great influence on the quality of concrete floor, especially on the large area concrete floor of industrial workshop in soft soil area. Due to the large equipment quality and uneven layout, the construction requirements for large-area concrete floor are higher. The joint workshop project of Tianjin Cigarette Factory of Shanghai Tobacco (Group) Co., Ltd. is a group workshop with a total construction area of 75 333m2 and a building height of16.8m. The workshop and overhead warehouse are grid structure and portal steel frame structure, and the auxiliary production room is 1 ~ 3-storey reinforced concrete frame structure. The workshop covers an area of 48 000 m2, including the silk-making workshop. Because this project is located on a thick backfill soil layer with soft soil, improper construction method will easily lead to uneven ground settlement, ground cracks and flatness failing to meet the design requirements, which will affect the installation and use of plant equipment. The following measures have been taken in the construction of this project: ① Drive 12 800 CFG piles into the foundation, and arrange them evenly and symmetrically; (2) Backfill graded macadam with a thickness of 500mm, and level and compact it; (3) pouring 250 thick plain concrete; (4) The upper part is poured with 250mm thick reinforced concrete to ensure the overall rigidity of the upper part; ⑤ Set permanent frame joints on the second floor of concrete to unify construction joints and frame joints, so as to avoid surface cracks of large-area concrete floor due to concrete shrinkage; ⑥ In the construction of 5mm thick ground surface, strictly control the thickness and smoothness of the surface, as shown in figure 1. Through reinforcement, the cast-in-place concrete floor slab is smooth, with clear lines, and no uneven settlement and cracks are found. This technology provides rich experience for the reinforcement of large area concrete foundation in soft soil area. Construction technology of large-area steel structure PVC roof Steel structure roof usually adopts profiled steel plate, including skylight, ventilation hole, various equipment pipes and supports, lightning protection network and supports, sink, parapet and other roof structures. These structures are all rigid materials, so it is difficult to deal with the waterproof problem at the joint with the roof, especially at the back opening of some roofs, water leakage often occurs, which affects the use of buildings. How to solve the water seepage problem of steel roof is also an important problem in the construction of industrial workshop. Xi 'an Aircraft Industry (Group) Co., Ltd. No.369 assembly workshop project, with a total length of 260m and a span of 80m, has a total construction area of 26,966m2, a building height of 35.20m and a roof area of 20,984m2, all of which are PVC coiled materials. A profiled steel plate is installed on the roof steel structure, and PE film moisture-proof layer, rock wool insulation layer and PVC coiled material waterproof layer are laid on the profiled steel plate, as shown in Figure 2. Engineering practice has proved that PVC polar polymer waterproofing membrane has the advantages of high tensile strength, good elongation, good weldability, convenient roof reconstruction and maintenance. In addition, PVC waterproof coiled material has light surface color, can reflect ultraviolet rays, has good water vapor permeability resistance and strong permeability resistance, maintains flexibility at low temperature (-30℃), is suitable for roof construction with various complex shapes, is simple in operation, safe and clean, can speed up construction and reduce construction cost. In addition to this project, part of the roof of the joint workshop of Tianjin Cigarette Factory of Shanghai Tobacco (Group) Company has also adopted PVC waterproofing membrane. In the review of high-quality projects, two projects have been used for more than 1 year, and no water leakage has been found. Conclusion The establishment of China Luban Prize for High-quality Construction Engineering not only improves the social popularity of enterprises, but also accelerates the scientific and technological development of construction enterprises, promotes the improvement of engineering quality in China, and plays a positive role in accelerating technological innovation. 20 10 luban prize national quality projects are mostly science and technology demonstration projects at or above the provincial level, and the construction methods are above the provincial level, and some projects also have national technology patents. Each high-quality project has its own characteristics, and there are new breakthroughs in building energy conservation and green building. It is believed that with the development of construction industry and the progress of science and technology, the quality level and technological innovation ability of national construction projects will be further improved under the impetus of creating high-quality projects.
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