ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
Six high-rise buildings of Hangzhou New Century Symbolic Building-Hangzhou Citizen Center Project stand tall on the Bank of Qiantang River. On July 13, 2007, six ring steel corridors manufactured and installed by Hangzhou Dadi Grid Manufacturing Co., Ltd. were checked and accepted. The six corridors have a height of 92m, with a maximum span of 57M and a weight of 650 tons. This scale and high degree of centralized lifting is also rare in the construction neighbourhood of steel-bonded truss in China. Fig. 1 is the general picture of the first corridor after it was successfully installed. The main project of Hangzhou Citizen Center is a six-barrel tower. There are 2 underground floors and 26 above ground floors. There are annular steel-bonded corridors at 23-24 floors (elevation 84.692.0m). Six towers are connected into a whole through six corridors. The total building area of six corridors is about 6896 square meters. The location of the steel corridor is shown in Figure 2 below. Structural features: The steel structure connecting truss is a 8.1 meter high bismuth truss.
Six steel corridors have two divine specifications: the outer ring truss span of R1 and R4 steel corridors is 57.280m, the inner ring truss span is 47.012m, and the total width of corridors is 20.97m. The weight is 650t, the outer ring truss span of R2, R3R5 and R6 steel corridors is 34.060m, the inner ring truss span is 27.954m, and the total width of corridors is 19.7m. It weighs 360t. Fig. 3 below is the Falcon model of R1. The main skeleton of the steel corridor is composed of two large Sui Dynasty trusses and five horizontal trusses. The floor and roof planes are composed of cross-arranged beams. Some of the beams are made of H-shaped steel and the material is QB. The maximum member section is = 600 × 400 × 35. This paper takes the hoisting of R1 as an example to describe the hoisting scheme. Because the installation height of the steel structure corridor is 91.8m and the weight of many components is large, it is difficult to guarantee the quality of the high-altitude bulk, and the scaffolding of such a high level is even more difficult to imagine.
Therefore, this installation scheme is not considered. Considering that the installation of corridor is carried out after the main structure is sealed. Therefore, it is very obvious to regard the completed main structure as the lifting force body. Then the steel structure corridor is lifted in place by using super-large hydraulic synchronous lifting technology. In terms of elevation and weight, there are many successful examples in China. However, for this project, because the steel-bonded corridor is placed between the two main structures, that is to say, the length of the corridor along the circumferential direction is greater than the net distance between the two main buildings. In this way, if in-situ lifting is carried out according to the conventional method, it is necessary to make a splicing of the main body of the corridor at high altitude. In order to avoid high-altitude splicing, we design another adjustment scheme according to the characteristics of this project. From the layout of this project, it can be seen that the position of the steel structure corridor is a sector area, and the net distance of the outer ring is larger than that of the inner ring. Therefore, if we move the assembly site of the corridor from the original plane position to the outer ring, we can assemble the corridor in the ground without any division in the circumference. After vertical elevation to the design elevation, we can achieve the original plane position by a radial translation.
In this way, a hydraulic synchronous movement is added to avoid high-altitude splicing. The construction plan of this project is as follows: "Ground assembling, hydraulic synchronous lifting, high altitude synchronous sliding, hydraulic drop in place. As shown in Figure 4, the dotted line is the contour line of the front corridor before slipping, and the solid line is the contour line after being put in place. In order to realize the above-mentioned overall hoisting idea, the following problems need to be solved. This is also the technical key point of this project. 1. Deepening the design and processing, considering the transportation and site conditions, we will control the length of the transport single piece segment to 20. For the most important inner and outer ring truss, it is divided into three sections in the circumferential direction and two sections along the altitude direction. The upper surface of the middle chord is spliced on the spot. In this way, the lower web bar and the lower chord bar of the middle chord become a Yunhan element, and it is easy to ensure the accuracy of the connection between the upper web bar and the middle chord bar. Fig. 5 is the outer ring truss diagram, and the dotted line is the location of the segments.