ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
The narrow site and poor construction conditions are the common difficulties in current construction projects. For high-rise steel structure projects, the relatively tight construction period requires higher and stricter stacking of components. If this problem is not handled properly, it will have a serious impact on lifting and the construction of the whole project. In the early stage of construction of Jinlong Mansion, due to the large number of components piled up and the large amount of steel structures entering the site, it is necessary to stack 2-3 stories. If there is no meticulous entry plan, it will inevitably lead to the confusion of the entry sequence of components on the site. The result is that the required components are pressed below and the unused components are placed on the top, not only the acceptance work can not be carried out, but also there are a lot of dumped materials. Repeated work such as finding materials. Later, on the basis of strengthening site management and component access plan, the work of site component stacking arrangement and component stacking sequence was emphasized. In addition to Zhou Du's accessory parts according to lifting requirements, the accessory parts were orderly arranged according to lifting sequence and characteristics of stacking site planning, which not only ensured the normal process of acceptance work, but also ensured the normal progress of acceptance work. The acceptance of components with good external conditions created by installation is our experience in the past construction of high-rise steel structures.
There are 5000 steel components in Jinlong Building. It is unavoidable that some problems will arise in the process of manufacture and transportation. If these problems are not eliminated on the ground, the installation degree will be increased when lifted onto the building, which will have a serious impact on the quality control of the whole project. 2.2 The selection, arrangement and disassembly of tower crane are the core equipment in the construction of high-rise steel-bonded truss project. The selection and arrangement of tower crane should be considered comprehensively according to the layout of buildings, site conditions and weight of steel-bonded trusses, and ensure the safety, convenience and reliability of erection and disassembly, as well as according to the construction site, structural shape and component of Jinlong Tower. Maximum lifting weight, choose a TC7030-16 tower crane. 70 meters radius of rotation, terminal lifting weight of 3 tons. According to the calculation of lifting weight from tower crane to each farther silk point and each lifting point, all steel columns and beams meet the lifting requirements. In the demolition of tower crane, we adopt the method of `big to small, small to zero', which better solves the problem of demolition room of tower crane. 23 Lifting silk is the leading process of steel structure construction, so-called good start is half the success.
” The speed and quality of installation play an important role in the whole project. In the construction of high-rise steel structure of Jinlong Mansion, the contradiction between tight construction period and large amount of work is solved by the method of regional hoisting through the cooperation of several installation machines. In the process of hoisting, 25 tons of truck crane is used to hoist the first section of steel column in the high-rise construction area, while TC7030 is mainly used to hoist the crane with two or more columns for unloading. ) 2.4 The deviation of verticality, axis and elevation is an important index to measure the quality of high-rise steel structure construction. As the control stage of Engineering quality, measurement must provide basis for construction inspection. From the construction process of steel structure, it can be seen that each process is interrelated and mutually restrictive. The choice of measurement and control methods directly affects the progress and measurement of the project. After entering the site, the technicians and surveyors of our company, with the support and cooperation of the general contractor, supervision unit and construction unit, handed over the axes and elevation control points in writing, which served as the basis for installation, measurement and correction inspection.
For axis control, theodolite is used to measure the axis and check the capital. First, the axis bullet is set on the basement floor, and then the steel column is divided into central lines. For plane control: we use four control axes and eight control points (internal control points) to set up the axis on the floor according to the square bottom plane and rectangular upper plane of Jinlong Building. For verticality control, we use two theodolites in two different directions. When the steel column is installed to a certain height, a survey control point is set up in the northeast and northwest of China, which can provide the visual condition of the steel column with more than 3 columns in this direction. For the control of elevation: the elevation in the foundation pit is realized by transferring the elevation control points on the ground to the pit according to the leveling survey method and setting temporary elevation control points in the pit. The special delivery of floor elevation control points is carried out vertically along the exterior walls, side columns or elevators of the structure. The 2.5 welded steel structure has the characteristics of tight construction period, complex structure, large quantity of work and high quality requirements. Welding is an important process of steel structure construction, and the selection of its process and welding level are of great importance to the safety, quality and quality of the project. The completion of "high speed" has a significant impact.
According to the characteristics of the project, we have worked out a set of practical manual arc welding (SMAW) process instructions suitable for the project, and established the relevant process parameters. According to the requirements of welding process, the welding rod should be baked according to the welding process before construction, and placed in the insulating cylinder of the welding rod when it is used, and the record should be filled. Welding sequence should be expanded symmetrically from the middle to all sides in plane. Vertical measures can be taken to facilitate process adjustment, facilitate construction and ensure that welding passes through the preparation of welding process instructions. Welding quality has been effectively guaranteed, economic benefits and construction duration have also been effectively guaranteed, and letters from general contractors and construction units have been obtained for us. Ren He was highly praised.