ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
The steel structural steels of this project are mainly Q345, Q390, Q420 and Q460, which are made of GS-20Mn5V steel plate, with high strength requirements, thicker joints and component walls, high weld height up to 54m, and large amount of work at high altitude. Under high altitude environment, the welder's operating scene is very loud, and the high altitude wind speed is high, which runs through the whole process of field welding. Especially for the gas shielded arc welding jingzan rotating structural members are inclined bending and torsion members. The welded joints are basically in front position. The welder's operation level requires high welding workload. The consumption of welding materials on site will reach 1_0t. According to the six-month installation period, the average consumption of welding materials reaches about 167 per month, and the welding workload is comparatively high. 60% of the total length of welded seam in welding material construction is first-class fully penetrating butt joint. 100% _T inspection requires that the structure should be assembled into two separate plates at high altitude in the process of installation of 36-closure steel structure. In order to ensure the safety of the structure in use, appropriate closure temperature should be selected. Temperature changes will cause great changes in the structure. Force and deformation will have a significant impact on the safety of the structure. A series of control measures must be taken to control the closure temperature of 36.1 steel structure. The design of this project requires that the closure temperature be 15 ~2036.2 when measuring the closure temperature of the steel structure. In order to accurately grasp the distribution of the whole roof steel girdles, as well as the overall temperature of the structure, the closure temperature of the steel structure should be measured at the closure temperature of 15 ~2036.2. The optimal closing time is determined by the corresponding relationship between the actual temperature of steel structure at different locations and temperature. The measuring range of the system is within 1 C, and the measuring accuracy is 1 C.
Temperature measurement consists of 9 points, 8 points symmetrically arranged on the outer side of the structure, and 1 point at the central square. Temperature measurement points are arranged in Figure 7 (Mobius ring steel structure). An automatic temperature measurement system using thermocouples as temperature measurement elements is specially established. Temperature measurement begins 5 days before the closure of Helong and covers all the work of the closure process. For the continuous measurement data of Xingcheng, the temperature information of each measuring point is read at 0.5-1 h interval, and the data files are formed. The key point is to collate and analyze the night temperature of each measuring point in order to obtain the overall temperature of the steel structure at night. Volume value and distribution 36.3 Closure installation points control 1) As far as possible to choose the closure temperature similar to or below the temperature conditions for installation, in order to facilitate the entry of components, control the closure of the size of the ramp to take into account the calculation results of temperature deformation and welding shrinkage deformation, in order to reduce the closure of the welding volume and welding. Residual stress ensures that the groove clearance at the first welding end of the integration section is ensured. At the same time, the amount of staggered edges of the closure should be controlled to ensure the smooth closure. 2) The small clearance installation method should be adopted to avoid excessive closure clearance at closure. 3) In order to ensure the safety of the closure section during construction, after the closure section is installed in place, except the closure required by the design. The other joints should be welded in time to enhance the overall stability of the structure. 4) In order to ensure that the closure can be freely closed due to temperature changes in the construction process, the size and quantity of the Kama should be determined according to the calculation of the stress at the interface. This calculation of the stress should not only consider the closure. The acceptance requirement during the installation of section 5) Closure sequence control in the process of closure 5) Closure sequence control in the logbook of hot sage due to t condition, while the closure of the meat point Dafa Jiuyou Yaomin 7 body from the closure mouth and welding 37 is considered as complicated.
The space steel-bonded structure, the support reaction force and the unloading deformation of each support point are quite different. To achieve the overall unloading of 399 supports, it is very difficult not only to implement the hardware conditions of unloading, the overall control and management of unloading, but also to achieve the synchronization accuracy. According to the actual situation of the project and the stress and deformation characteristics of the whole steel structure, the general principle of "step by step" unloading is determined, and the unloading process follows the principle of "reasonable and orderly".