Abstract: A giant single-span underground cavern under construction faces technical issues of a large amount of rebar binding and concrete casting as well as high construction risks. Moreover, the simple platform is too complex and huge to move easily and work effectively. Based on the technical advantages of a fully-hydraulic steel form-lined trolley and modular high-performance Beret frame, a construction equipment integrating the functions of rebar binding and concrete casting is developed for the secondary lining construction of giant-span caverns. The equipment is supported by a Beret frame with a walking mechanism at the bottom, a concrete casting steel formwork, and a steel binding working platform at the top. Hydraulic and electrical control as well as driving technologies are used to assist the construction with various automatic mechanisms, which can achieve one-time positioning and simultaneous steel binding and concrete casting. The application results reveal that the integrated equipment can effectively reduce the artificial labor intensity, improve efficiency, ensure the construction quality, and control the construction risk.

Key words: giant-span underground cavern, integrated equipment for secondary lining construction, Beret frame support system, steel binding, concrete casting