ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
Key technical problems in this project are the heavy weight and large volume of large section arc box girders. When making arc box girders on the tyre frame, the tyre frame is easy to be wound down. Therefore, checking calculation before making the tyre frame ensures that the deflection of components is controlled within 1 mm when applying pressure on the tyre frame. Because the tyre frame needs to be repeatedly used, the planar leveling of the tyre frame is required by the personnel before making the dock. The flatness allowable deviation is controlled at (+1 mm). If there is deviation, the lower bottom of box girder should be adjusted in time to be arc plate with large width. The oxide skin on the surface of steel plate should be removed before rolling plate, and protective film should be coated. When rolling round, crane should be used to reduce the weight of steel plate and make the steel plate straighten back according to the general order of actual engineering situation. And the optimal welding sequence is calculated by ANSYS three-dimensional simulation software. The maximum chord length is 13.7m, the maximum height is 1.5m, and the maximum width is 4m. Therefore, we determined that the minimum area of the new frame is 14m*4m=56m2.
The maximum weight of steel box girder is 2 and according to these original data, the deflection of the frame is controlled to 1 m. The cross sections of the truss frame and platform foundation frame with sufficient bearing capacity are designed as follows (Fig. 22 layout points, flattening 151-LINE5 altogether. The unified elevation is measured by each collimator. LINE6 and L7. First, the elevation difference between adjacent points is calculated by mathematical formulas, and then the leveler is used to calculate the elevation difference between adjacent points. Measuring the elevation of each point, checking the difference between the measured elevation difference and the calculated elevation difference between the adjacent points, making a section of steel box girder, then re-placing and recording in detail, if the qualified rate is less than 95%, adjusting and strengthening to the qualified rate is 95%, then making the pre-bending accuracy control of the lower section steel girder and plate machine. The workshop technical person in charge formulates the operating rules of the plate rolling machine, which is totally recorded by the unit. After the approval of the project, it will be put into effect and handed over to the construction team leader to order the small slideway friction strip, so as to make the lubricating oil of the oil tank unobstructed and so on. In order to reduce the self-weight of the steel plate, a 10-ton crane is used to work with the winding machine (Fig. 5). Workers are arranged to continuously measure the arc inside, and the segmented comparison sketch of the scaled oxide template is blown away (large section arc box steel bridge). The precision of bending arc parts is 4% higher than the original 76. Although the qualified rate is not up to 00%, the bending method greatly improves the precision of arc parts.