ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
2.7. Fudong Tower with special joints is a special structure with large and complex forces. Therefore, various types of joints in Fig. 3 are selected. 3. Determination of hoisting scheme 1. Installation method of external support system: First, the steel used in external support system is large and uneconomical; secondly, it can not meet the unstable phenomenon of the inclined part above 74m; thirdly, synchronous construction of the surrounding buildings and the tower installation, unconditional pinching of support frame. 32. Installation method of internal support system: at 79M elevation, support truss is installed inside. Firstly, the amount of steel used is small; secondly, the construction site is not occupied; secondly, it plays a supporting role, that is to say, it solves the problem of 54m-74m extroversion stability and 74m-109m introversion stability, and its technical and economic effects are obvious. 33. Considering the local deformation of steel columns caused by each layer of steel bars, concrete and civil construction loads, in the calculation of pre-adjusted deformation, the steel frame and civil construction are staggered by 0-54m to install about 10m to 54m-117m steel frame to install 20m 9m-84m to install the horizontal support truss in advance of civil construction.
4. Structural hoisting and equipment selection of steel-reinforced structures below 4.1 m and 24 M. Since lifting equipment is not allowed in the tower and peripheral tower silk is unconditionally set up in the construction stage below (+0), all structures of - 19m-24m are hoisted by a 400t and a 300 crawler, and two 50t trucks are hoisted upside down. The quadrangular cylinder body is erected first and then the operating platform is pinched, which is installed from inside to outside and accumulated layer by layer. Because there is no tangential inclination in this part, the installation process is similar to that of Yintong high-rise steel structure. The main reason for the adoption of this layer scheme is that the underground structure is installed, and the upper structure is installed immediately. The installation of 4.2 m and 24m-44m determined by the tower silk is not installed in place. The installation sequence is: steel column wall limb steel frame channel steel wall limb beam steel frame. All the steel columns are hoisted as a whole. First the vertical steel columns are hoisted, and then the oblique steel columns are hoisted. Four externally attached tower cranes are used for lifting. The main crane is MC480 type and the auxiliary silk is MC320 type. Two of them are arranged diagonally. The radius of the boom is 40m. The maximum lifting weight is 25t, first inside the tube and then outside the tube. The steel column is first followed by the steel beam (wall limb). The vertical steel column is first followed by the oblique steel column. Finally, the horizontal steel beam between the barrels is installed with the installation of 4.3 and 44m-54m. The section is the most complex and consists of the following parts: first, the steel beams between the four corner cylinders and the connecting parts between the trusses and the wall column cylinders; fourth, the dome in the middle; fifth, the steel beams at the top of the dome.
As one of the main transfer stories of the whole structure, the most reconstructed layer plays a connecting role in the whole structure, so it determines the particularity of this part of the structural components, and the complexity of the structural layout of the components, especially the truss and dome, brings some difficulties to hoisting. Based on the analysis of knot truss, the hoisting sequence is as follows: first four corner tube members, then truss, then dome, and finally installation of beam. The lifting of the truss is the difficulty and key point of the installation. The smooth installation of the truss is the precondition to ensure that the construction period and the steel structure do not affect the subsequent concrete construction. Eight heavy trusses are installed by double cranes. The main installation measures are as follows: first, the tower crane load is not more than 80% of the allowable lifting weight, the driver and commander of the same vehicle must have lifting experience; fourth, the observation should be strengthened in the lifting process. See the chimney for details.