Design Method and Impact Response of Energy-Consuming High-Fall Flexible Protection System for Construction

High-fall accidents refer to accidents where construction personnel, building materials, and equipment fall from a height, usually resulting in serious casualties and significant economic losses. This paper proposes a high-fall flexible protection system and its design approach with a tensile yield energy-consuming mechanism to solve high-fall accidents. The design approach based on component characteristics that obtained through tests contains energy matching, component internal force balance, and a two-level energy consumption mechanism. Component tests were conducted with mesh bursting tests and energy dissipator static tensile tests to obtain the characteristics of the intercepting net under the flexible boundary condition, and the force-displacement model of the ring-type energy dissipater. Combined with an actual project, we designed a high-fall flexible protection system with a protection energy level of 800 kJ for the core tube of an ultra-high-rise building construction using this method. The impact of dynamic response under multiple cases including the overall fall of the construction formwork was analyzed by dynamical numerical calculation models. The result shows that the system can effectively intercept high-falling objects and exhibit good two-stage energy dissipation characteristics to consume the impact energy. Compared with the protection system without an energy consumption mechanism, the internal force response of the steel wire rope and the suspended frame reduce by about 60%, and the energy consumption capacity increase more than six times. The protection technique proposed in this paper can effectively solve the problem of high-level impact protection such as falling construction formwork equipment, and improve construction safety.