Research on Structural Design and Construction Technology of Protection Umbrella for Deep Foundation Pits in Transmission Lines

Addressing the safety threats posed by falling soil lifting frames during deep foundation pit construction in transmission lines, a novel protection umbrella device for deep foundation pits was designed and studied. The device adopts an integrated structure combining support rod components with arched plate components, and through adjustable height design, it adapts to foundation pit operations within the depth range of 10~16 m. The mechanical principles, geometric characteristics, and key technical parameters of the device were elaborated. An impact force decomposition model and height adjustment calculation method were established, and a staged protection technology along with an installation positioning scheme were proposed. Impact test results indicate that the device achieved a 100% protection success rate under loading conditions of 177 kg and 150 kg, with overturning characteristics meeting design expectations and an injury risk reduction rate exceeding 92%, thereby providing effective technical safeguards for deep foundation pit construction safety.