Research and Implementation of Construction Plan for Long-Span Steel Corridor in Egyptian CBD Project

In recent years, long-span high-altitude conjoined steel structures have been widely used in various complex large-scale public buildings, such as the new headquarters building of CCTV in Beijing, Raffles City in Chongqing, and the Marina Bay Sands Hotel in Singapore, of which the construction methods are very complex and difficult. For the design of the hotel in the Central Business District(CBD) project in the new administrative capital of Egypt, the form of a high-altitude long-span steel structure corridor was also adopted. The steel structure corridor plane is arc type, a total of 2 layers, the height of the first layer is 9.0 m, the height of the second layer is 6.5 m, the maximum span of the outer arc is 43.0 m, the width is 24.0 m. The total weight of the steel structure corridor is about 600 t. According to the characteristic of steel structure corridor, and combined with domestic and foreign long-span high-altitude conjoined steel structures construction methods, two construction hoisting schemes were proposed according to the characteristics of the steel structure corridor. Scheme 1 adopts the method of "segmented hoisting and high-altitude connection". After installation completed on the ground, the fragments are hoisted in a reasonable order and the overall connection is completed in the air. Scheme 2 adopts the method of "high-altitude cantilever bulk installation". The steel truss members are hoisted one by one at the end support position, and are butted together at the mid-span position to form a space truss. Comprehensively considering factors such as construction period requirements, cost requirements, quality requirements, safety requirements, and the ability of local workers, the construction method of Scheme 1 was proposed.
The construction process simulation method was used to calculate and analyze Scheme 1. The results show that the vertical displacement of the main truss and the component stress ratio are small during the installation of the steel structure, the hoisting sequence is reasonable, and the lateral support is effective, which can meet the requirements of steel component stability and construction precision control during the construction process. The feasibility of the scheme has been verified. At the same time, in order to ensure the safety and quality of the construction process, a number of key control measures have been adopted. Super crawler crane was used to ensure the safety of the hoisting process; temporary supports were set to ensure the stability of components during the construction process; and adjustable tie rods were set to control the levelness of components; it set strict control the daily work time to avoid temperature differences from affecting the installation accuracy, etc.